Circadian typology is related to emotion regulation, metacognitive beliefs and assertiveness in healthy adults.

Circadian typology has been related to several mental health aspects such as resilience, perceived well-being, emotional intelligence and psychological symptoms and disorders. However, the relationship between circadian typology and emotion regulation, metacognitions and assertiveness, which constitute core constructs related to psychological well-being and psychopathology, remain unexplored. This study aims to analyze whether circadian typology is related with those three constructs, considering the possible influence of sex. 2283 participants (833 women), aged 18-60 years (30.37 ± 9.26 years), completed the reduced Morningness-Eveningness Questionnaire, the Emotion Regulation Questionnaire, the Meta-Cognitions Questionnaire 30, and the Rathus Assertiveness Schedule. Main effects were observed between circadian typology and cognitive reappraisal, metacognitions, negative beliefs of uncontrollability and danger, cognitive confidence, cognitive self-consciousness, and assertiveness (F(2,2276) > 4.80, p < 0.009, ηp2 > 0.004, in all cases). Morning-type participants scored lower than evening-type in general metacognitive beliefs, negative beliefs of uncontrollability and danger, cognitive confidence, and cognitive self-consciousness, and higher than evening-type in cognitive reappraisal and assertiveness, while neither-type exhibited intermediate scores (p < 0.033 in all cases). According to the results, evening-type individuals might display a higher tendency to support maladaptive beliefs about thinking itself as well as a lesser tendency to reappraise a potentially emotion eliciting situations in order to modify its meaning and its emotional impact and to exert their rights respectfully. This new evidence improves the understanding of the relationships between circadian typology and psychological factors related to psychological well-being and psychopathology. Results implications for the onset and maintenance of psychological problems are discussed. Although future longitudinal studies are needed, results emphasize evening-type as a risk factor for the development of psychological disturbances and morning-type as a protective factor against those.

Introduction

During the last decades there has been an increase in the interest in studying the associations between morningness-eveningness and the so-called circadian typologies and mental health related-factors such as satisfaction with life and well-being [1,2], resilience and optimism [3], emotional intelligence [4], maladaptive coping strategies [5], personality traits related to risk behaviors [6], psychological symptoms [7,8] and psychopathology [9].

Morningness-eveningness is a dimension that tends to follow a normal distribution and allows for classifying the population in one-of-three circadian typologies or chronotypes: morning-, neither-, and evening-type [10]. The first ones are used to go to bed and wake up earlier, are more adjusted with the night-dark cycle and, therefore, show a phase advance of their biological and behavioral circadian functions as compared to evening-type, who tend to go bed and wake up later and are little adjusted with the light-dark cycle. Regarding prevalence, it is estimated that morning- and evening-type represents about 40% of adult population (around 20% for each one) while neither-type, which tends to maintain an intermediate position between extreme groups, compounds the remaining 60% [11].

The higher synchronization with the light-dark cycle in the morning-type may be the cause of the tendency to suggest this chronotype as a protective factor for the incidence of psychopathology [12], even suicidality [13], while evening-type has been suggested as a risk factor for the development of mental disturbances and psychological symptoms [9,11,14,15]. Those differences might be explained by the social jet-lag [16], which occurs when the social and the biological clocks are out of sync with each other.

Other relevant factors commonly related to circadian typology are age and sex. On the one hand, childhood and elderly populations have shown higher morning-type prevalence that contrasts with the evening-type predominance found in adolescents. After adolescence and during the adulthood it has been shown a slow but consistent shift toward morningness [17,18]. On the other hand, although some studies about circadian typology showed a greater tendency to morningness in women [19-21], even by assessing the circadian rhythmic expression [22], others have found the opposite [23-25]. In this line, psychosocial factors such as meal times, work schedule, family relationships and child care have been proposed as an explanation for this controversial [17].

Emotion regulation, known as the ability to regulate emotions in order to succeed, has been a widely studied subject during the last three decades [26] that has emerged as one of the pillars of well-being and social functioning [27-33]. According to a process model of emotion regulation, emotions may be regulated in five points along the emotion generative process: (1) selection of the situation, (2) modification of the situation, (3) deployment of attention, (4) change of cognitions (meanings) and (5) modulation of the experiential, behavioral or physiological responses. The first four points allow antecedent-focused emotion regulation, while the last allows response-focused emotion regulation [32]. Cognitive reappraisal and expressive suppression constitute two emotion regulation strategies commonly used in everyday life. The first, which is defined as the attempt to reappraise a potentially emotion-eliciting situation in a way that modifies its meaning and changes its emotional impact, is an antecedent-focused emotion regulation strategy and, due to its relationships with well-being, is considered an adequate strategy [27,32,34]. Expressive suppression, on the other hand, is defined as a form of response based on the inhibition of the emotion-expressive behavior and, therefore, is a response-focused emotion regulation strategy. Moreover, this strategy is more used by men and commonly categorized as maladaptive due to its relationship with depression and anxiety [27,32,33,35].

A field directly related with emotion regulation and psychopathology that has received an increased scientific attention during the last three decades has been metacognitions. In this line, although it is well known that emotions exert an important influence in cognitions [36], it is also known that metacognitions exert a central role for the development and persistence of emotional dysfunctions [37]. Metacognitions refer to the psychological structures, knowledge, events and processes involved in the control, modification and interpretation of thinking itself [38]. The self-regulatory executive function model [39] states that beliefs in psychopathology are the result of a metacognitive component that guides think and cope activity. In this sense, metacognitions lead to focus on disorder congruent information and to use maladaptive coping strategies [38], which is in line with the generic cognitive model [40]. Several studies using the Meta-Cognitions Questionnaire [38], which assess a range of metacognitive domains related with psychopathological processes such as low cognitive confidence, positive beliefs about worry, cognitive self-conscientiousness, negative beliefs about uncontrollability and danger, and belief concerning the need to control one’s own thoughts, have shown a strong relationship between those and several psychological disorders and symptomatology. In this line, metacognitions have found to be related to different psychological issues such as depression [41], bipolar disorder [42], obsessive-compulsive disorder [43], generalized anxiety disorder [44], anxiety [45,46], gambling [47], substance use disorder [48] and eating disorders [49].

Assertiveness, known as the ability to affirm a right or a point of view without either aggressively threatening the rights of another nor submissively allows another to deny one’s rights or point of view is another construct that has been found related to metacognitions [50]. This construct, which is considered as a continuum with excessive agreeableness (submissive or unassertive) and excessive hostility (aggressiveness) in the poles, has gained much attention from the psychotherapy field as its training is considered a valuable transdiagnostic intervention [51]. Several research studies have shown a link between assertiveness and clinical problems such as depression [52], anxiety [50,53,54], and serious mental illness [55], as well as with other constructs related to well-being such as self-esteem [54], relationship satisfaction [56,57], happiness [58] and meta-cognitive beliefs [50].

The aim of this work was to examine, for the first time, the relationships between circadian typology and three constructs related with psychopathology and well-being: Emotion regulation, metacognitions and assertiveness, considering the possible influence of sex, in a wide sample of healthy Spanish adults without physical or mental pathology. It is hypothesized that evening-type participants will score higher than morning-type in metacognitions and expressive suppression, while morning-type will score higher than evening-type in assertiveness and cognitive reappraisal.

Materials and method

Participants

The total amount of participants in the study was 3016, out of which 733 were excluded due to duplicate answers and for non-accomplishing the inclusion criteria (Spanish resident, absence of mental and physical health problems, absence of shift work and 18–60 yrs). The final sample included in the study was composed of 2283 adults, Spanish residents, aged 18–60 (30.37 ± 9.26 yrs), 1450 men (63.5%) and 833 women (36.5%). Age differences were observed between men (29.44 ± 8.39 yrs) and women (31.93 ± 10.34 yrs) (t(2281) = 6.25; p < 0.001; Cohen’s d = 0.26). Participants did not receive any payment for their participation in the study and they all gave their informed consent prior to the inclusion in the study. Subjects submitted their answers on online questionnaires of circadian typology, emotion regulation, metacognition beliefs and resilience and provided self-reported information about sociodemographic variables and the presence of any mental or physical pathology. The present study, whose protocol was approved by the Research Committee of the University of Málaga, complied with the tenets of the Declaration of Helsinki and the international ethical standards of chronobiological research [59].

Measurement instruments

The reduced Morningness-Eveningness Questionnaire (rMEQ), in its standardized version for the Spanish population [60], was used for the assessment of circadian typology. The rMEQ is composed of five items with total score ranging from 4 to 25 points. Participants are assigned to one of the three possible circadian typologies (morning-, neither-, or evening-type) according to the cutoff score: 4–11 for the evening-type, 12–17 for the neither-type, and 18–25 for the morning-type. The Spanish version of the rMEQ has been shown as a reliable measure for classifying individuals in the morningness-eveningness dimension [61] and its internal reliability was adequate for the present sample (Chronbach’s α = 0.78).

Emotion regulation was assessed using the Spanish version of the Emotion Regulation Questionnaire (ERQ) [32,33], which is composed of ten items in a Likert scale format with scores ranging between 1 (strongly disagree) and 7 (strongly agree) for each one. The ERQ assesses two different emotion regulation strategies: Cognitive reappraisal, with 4 items and total score ranged 4–28, and expressive suppression, with 6 items and total score ranged 6–42. Higher score implies a higher use of the strategy. The ERQ shows good psychometric properties and is considered as a reliable and valid instrument for assessing emotion regulation strategies [32,33]. For the present sample, internal reliability was adequate for both strategies, with a Chronbach’s α of 0.83 for expressive suppression and of 0.81 for cognitive reappraisal.

Metacognitions were measured using the Spanish version of the Meta-Cognitions Questionnaire 30 (MCQ-30) [38,62]. This questionnaire, which comprises five subscales, is composed of 30 items with a 4-point Likert scale response format, ranging from 1 (do not agree) to 4 (strongly agree). Total score ranges from 40 to 120 points and higher scores are indicative of greater pathological metacognitions. The five subscales assess positive beliefs about worry (“worry is useful for avoiding future problems”), negative beliefs of uncontrollability and danger (“my worrying might be dangerous for me”), cognitive confidence (“I do not trust my memory”), need to control thoughts (“I should be controlling my thoughts all of the time”) and cognitive self-consciousness (“I am constantly aware of my thinking”). Internal reliability analyses with the present sample have shown adequate scores for the total score (Chronbach’s α = 0.90) as well as for each subscale (Chronbach’s α = 0.89 for positive beliefs about worry; 0.83 for negative beliefs of uncontrollability and danger; 0.86 for cognitive confidence; 0.73 for need to control thoughts; and 0.85 for cognitive self-consciousness).

Assertiveness was assessed using the Spanish version of the Rathus Assertiveness Schedule (RAS) [63,64], which is composed of 30 items in a 7-points Likert scale format ranging from -3 (very much unlike me) to 3 (very much like me), with total scores ranging from -90 to 90. RAS has been consolidated as a reliable and valid instrument for assessing assertiveness due to its adequate psychometric properties [65]. Likewise, internal reliability was adequate for the present sample (Chronbach’s α = 0.86).

Data analysis

Two multiple analyses of covariance (MANCOVA) and two single analyses of covariance (ANCOVA) were performed, each one with circadian typology and sex as factor and with ERQ, MCQ-30 subscales, RAS and MCQ-30 total scores as dependent variables, respectively, whereas age was taken as a covariate to control for possible effects. Post-hoc comparisons were adjusted by Bonferroni’s correction and the partial eta square η2 was obtained as a measure of the ANCOVA effect size, considering 0.01 as small, 0.04 moderate, and 0.10 large. Three multiple stepwise regression analyses were performed, each one for scores on ERC, MCQ-30 and RAS as dependent variables, respectively, while sex and age (first step) and rMEQ scores (second step) were the independent variables. Cohen’s f2 was used as effect size, considering scores of 0.02 as small, 0.15 moderate, and 0.35 large [66]. Statistical analyses were performed using the IBM SPSS 64 bits software (version 24.0) and statistical tests were bilateral with the type I error set at 0.01.

Results

Sociodemographic data

Subjects distribution along circadian typology groups was 636 for the evening-type (27.9%; 452 men and 184 women), 1115 for the neither-type (48.8%; 716 men and 399 women), and 532 for the morning-type (23.3%; 282 men and 250 women). The distribution of the rMEQ scores were skewed towards the eveningness pole (z = 3.27, p < 0.001). Likewise, significant differences were observed between women (14.78 ± 0.15) and men (13.67 ± 0.11) in rMEQ scores (t(1,2281) = 5.89, p < 0.001, Cohen’s d = 0.25). Circadian typology groups showed age-differences (F(2,2280) = 105.31; p < 0.001). Post hoc comparisons showed differences between all groups. Morning-type participants were older (34.91 ± 0.46 yrs) than neither- (29.85 ± 0.26 yrs; p < 0.001) and evening-type (27.49 ± 0.30 yrs; p < 0.001), who were younger than neither-type (p < 0.001). Table 1 shows sociodemographic (employment and marital status) according to sex and circadian typology groups. A higher proportion of workers and a lower one of students was observed in the morning-type group while students and workers percentage in the evening-type were even. Regarding marital status, it was observed a higher prevalence of women as well as morning-type participants in the coupled group while evening-type were more prevalent in the single group.

Table 1

Sociodemographic data according to sex and circadian typology groups.

	Age	Sex					Circadian typology
		Men		Women			Morning-type		Neither-type		Evening-type
	Mean ± SD	n	%	n	%	χ2	n	%	n	%	n	%	χ2
Employment status
Student	22.62 ± 3.49	393	27.1	242	29.1	10.81*	78	14.7	317	28.4	240	37.7	116.43**
Worker	34.68 ± 8.85	808	55.7	410	49.2		370	69.5	588	52.7	260	40.9
Study and work	27.81 ± 6.70	150	10.3	107	12.8		61	11.5	128	11.5	68	10.7
No-worker	32.31 ± 10.24	99	6.8	74	8.9		23	4.3	82	7.4	68	10.7
Marital status
Single	27.75 ± 8.34	752	51.9	353	42.6	18.18**	191	36.0	548	49.2	366	57.5	54.04**
Paired	32.85 ± 9.41	698	48.1	476	57.4		339	64.0	565	50.8	270	42.5

*p < .05;

**p < .01.

Emotion regulation

Descriptive data for the total sample as well as for sex and circadian typology groups in the Emotion Regulation Questionnaire is shown in Table 2. Significant main effects were observed for sex in cognitive reappraisal and expressive suppression while for circadian typology the significant main effect was in cognitive reappraisal. Post-hoc comparisons showed higher scores of cognitive reappraisal in morning-type as compared to evening-type participants (MD = 1.45, p = 0.002, Cohen’s d = 0.20). Regarding sex, women showed higher cognitive reappraisal scores (MD = 0.83, p = 0.008, Cohen’s d = 0.14) and lower expressive suppression scores (MD = 4.20, p < 0.001, Cohen’s d = 0.80).

Table 2

Descriptive statistics (mean ± SEM), F-tests and partial eta-square (η2) for the variables.

		Sex					Circadian typology
	Total sample (N = 2283)	Men (n = 1450)	Women (n = 833)	F	ηp2	Observed power	Morning-type (n = 532)	Neither-type (n = 1115)	Evening-type (n = 636)	F	ηp2	Observed power
Emotion regulation
Cognitive reappraisal	29.24 ± 0.14	28.89 ± 0.18	29.84 ± 0.23	7.01*	0.003	0.75	30.05 ± 0.30	29.18 ± 0.20	28.66 ± 0.28	5.72*	0.005	0.87
Expressive suppression	15.28 ± 0.12	16.89 ± 0.14	12.46 ± 0.19	275.45**	0.108	1.00	14.30 ± 0.26	15.19 ± 0.17	16.25 ± 0.24	2.58	0.002	0.52
Metacognitions
MCQ-30 total score	62.75 ± 0.30	64.07 ± 0.37	60.44 ± 01.49	22.16**	0.010	1.00	60.08 ± 0.60	62.52 ± 0.42	65.38 ± 0.58	6.27*	0.005	0.90
Positive beliefs about worry	11.27 ± 0.09	11.79 ± 0.11	10.37 ± 0.13	45.42**	0.020	1.00	10.98 ± 0.18	11.19 ± 0.12	11.66 ± 0.17	1.19	0.001	0.262
Negative beliefs of uncontrollability and danger	12.64 ± 0.09	12.61 ± 0.11	12.68 ± 0.15	0.34	0.000	0.10	12.14 ± 0.18	12.58 ± 0.13	13.14 ± 0.18	5.65*	0.005	0.86
Cognitive confidence	11.16 ± 0.09	11.21 ± 0.12	11.35 ±0.16	0.31	0.000	0.09	10.81 ± 0.17	11.31 ± 0.13	11.56 ± 0.19	6.38*	0.006	0.90
Need to control thoughts	11.49± 0.08	12.00 ± 0.10	10.6 ± 0.12	57.38**	0.025	1.00	10.85 ± 0.16	11.47 ± 0.11	12.05 ± 0.15	2.45	0.002	0.50
Cognitive self-consciousness	16.09 ± 0.09	16.46 ± 0.12	15.45 ± 0.15	13.89**	0.006	0.96	15.29 ± 0.19	15.97 ± 0.13	16.97 ± 0.17	4.79*	0.004	0.80
Assertiveness	0.27 ± 0.58	1.13 ± 0.71	-1.21 ± 0.98	3.80	0.002	0.50	4.25 ± 1.27	-0.66 ± 0.79	-1.41 ± 1.10	5.73*	0.005	0.87

*p < .01;

**p < .001.

Metacognitions

Descriptive data for the total sample and structured by sex and circadian typology groups is shown in Table 2. Significant main effects were observed in MCQ-30 total score, negative beliefs of uncontrollability and danger, cognitive confidence and cognitive self-consciousness for circadian typology. According to post-hoc comparisons, neither-type participants showed higher scores than morning-type in cognitive confidence (MD = 0.70, p = 0.012, Cohen’s d = 0.12) and scored lower than evening-type in MCQ-30 total score (MD = 1.94, p = 0.032, Cohen’s d = 0.21) and cognitive self-consciousness (MD = 0.65, p = 0.016, Cohen’s d = 0.23). Evening-type subjects showed higher scores than morning-type in MCQ-30 total score (MD = 3.13, p = 0.002, Cohen’s d = 0.17), negative beliefs of uncontrollability and danger (MD = 0.91, p = 0.002, Cohen’s d = 0.23), cognitive confidence (MD = 0.97, p = 0.002, Cohen’s d = 0.17) and cognitive self-consciousness (MD = 0.74, p = 0.02, Cohen’s d = 0.39).Regarding sex, significant main effects were observed in positive beliefs about worry, need to control thoughts and cognitive self-consciousness. In this line, men scored higher than women in positive beliefs about worry (MD = 1.27, p > .001, Cohen’s d = 0.35), need to control thoughts (MD = 1.29, p > .001, Cohen’s d = 0.38) and cognitive self-consciousness (MD = 0.74, p > .001, Cohen’s d = 0.23).

Assertiveness

Table 2 shows descriptive data structured for the total sample, by sex and by circadian typology groups in the Rathus Assertiveness Schedule. A significant main effect was observed only for circadian typology. Post-hoc comparisons showed higher scores in morning-type participants as compared to evening- (MD = 4.78, p = 0.02, Cohen’s d = 0.20) and to neither-type (MD = 4.86, p = 0.004, Cohen’s d = 0.18).

Regression analyses

Table 3 shows results of multiple regression analyses while Tables 4 and 5 show the model coefficients for each variable. The analyses revealed that sex and age were significantly related to cognitive reappraisal (explaining a 0.4% of the variance), expressive suppression (14.2%), assertiveness (0.7%), metacognitions (3.9%), positive beliefs about worry (5.2%), need to control thoughts (5.5%) and cognitive self-consciousness (6.6%), with p < .05 in all cases. Moreover, the inclusion of the rMEQ scores in the equation resulted in a significantly increase of the explained variance for cognitive reappraisal (0.5%), expressive suppression (0.3%), assertiveness (0.6%), metacognitions (0.8%), negative beliefs of uncontrollability and danger (0.9%), cognitive confidence (0.7%), need to control thoughts (0.3%) and cognitive self-consciousness (0.5%), with p < .05 in all cases.

Table 3

Results of stepwise multiple regression analyses.

	First step			Second step
	Sex & age			Sex, age & rMEQ scores
	R2	F(2,2280)	f2	R2	F(3,2279)	f2
Emotion regulation
Cognitive reappraisal	.004	5.60*	.004	.009	7.90**	.009
Expressive suppression	.142	189.55**	.165	.144	129.33**	.168
Assertiveness	.007	9.18**	.007	.012	10.39**	.012
Metacognitions
MCQ-30 total score	.039	47.29**	.040	.047	38.10**	.049
Positive beliefs about worry	.052	63.36**	.054	.051	42.23**	.054
Negative beliefs of uncontrollability and danger	.001	2.37	.001	.010	8.76**	.010
Cognitive confidence	.001	2.68	.001	.008	6.78**	.008
Need to control thoughts	.055	67.48**	.058	.057	47.31**	.060
Self-consciousness	.066	81.11**	.071	.070	58.46**	.075

*p < .01,

**p < .001.

Table 4

Multiple linear regression model coefficients for emotion regulation strategies, assertiveness and MCQ-30 total score.

	Cognitive reappraisal			Expressive suppression			Assertiveness			Metacognitions
	B	SE B	β	B	SE B	β	B	SE B	β	B	SE B	β
Step 1
Sex	-0.013	0.015	-0.017	-0.071	0.012	-0.112	0.239	0.063	0.080	-0.247	0.032	-0.159
Age	0.989	0.297	0.070	-4.256	0.240	-0.346	-2.934	1.205	-0.051	-3.018	0.617	-0.101
Step 2
Sex	-0.029	0.016	-0.040	-0.061	0.013	-0.095	0.170	0.065	0.057	-0.204	0.033	-0.132
Age	0.897	0.298	0.064	-4.198	0.241	-0.342	-3.310	1.206	-0.058	-2.783	0.617	-0.093
rMEQ	0.121	0.034	0.077	-0.077	0.028	-0.057	0.495	0.139	0.078	-0.309	0.071	-0.094

Table 5

Multiple linear regression model coefficients for the different metacognitions assessed through MCQ-30.

	Positive beliefs about worry			Negative beliefs of uncontrollability and danger			Cognitive confidence			Need to control thoughts			Self-consciousness
	B	SE B	β	B	SE B	β	B	SE B	β	B	SE B	β	B	SE B	β
Step 1
Sex	-0.073	0.009	-0.162	-0.021	0.010	-0.045	0.022	0.010	0.047	-0.063	0.008	-0.155	-0.113	0.010	-0.235
Age	-1.238	0.178	-0.143	0.123	0.187	0.014	0.077	0.195	0.008	-1.247	0.160	-0.160	-0.733	0.188	-0.080
Step 2
Sex	-0.073	0.010	-0.162	-0.007	0.010	-0.015	0.034	0.011	0.072	-0.056	0.009	-0.138	-0.102	0.010	-0.213
Age	-1.239	0.179	-0.143	0.199	0.187	0.023	0.143	0.195	0.015	-1.210	0.161	-0.155	-0.675	0.188	-0.073
rMEQ	0.001	0.021	0.001	-0.100	0.021	-0.102	-0.087	0.022	-0.085	-0.048	0.018	-0.055	-0.076	0.022	-0.075

Discussion

In this study, and for the first time, the relationships among circadian typology, emotion regulation strategies, metacognitions and assertiveness were examined in a wide sample of healthy subjects. Participants distribution according to the morningness-eveningness dimension was skewed toward eveningness, which is in line with previous studies performed with large samples [3,4].

Obtained results supported the hypothesis that morning-type participants showed the highest cognitive reappraisal, meaning a higher tendency to use this kind of antecedent-focused emotion regulation strategy, which implies the reappraise of a potentially emotion-eliciting situation in order to modify its meaning and its emotional impact. Moreover, in line with the regression results, it was found that the closer one is to the morningness pole, the greater tendency to use this kind of emotion regulation strategy and the lower to perform a response-focused emotion regulation strategy as expressive suppression is, and vice versa. According with previous studies, men showed a greater tendency to suppress their emotional expression [32,33]. Moreover, women tendency to reappraise potentially emotion-eliciting situations was higher than men, which constitutes a difference regarding previous works [32,33]. Nevertheless, the absence of interactive effect between sex and circadian typology suggests that the circadian typology obtained results are independent of sex.

This higher tendency to cognitive reappraise observed in morning-type fits in with those studies that state this chronotype as a protective factor against psychological problems [6,8,11], as the usage of this emotion regulation strategy together with morningness tendency has been linked to well-being [32,67] and quality of life [68-70], as well as to several variables that acts as protective factor against psychopathology such as positive affect [71,72], psychological adjustment [32,73] and resilience [3,74], among others.

Moreover, regarding regression results, a higher use of expressive suppression was observed for those participants closer to the eveningness pole. Expressive suppression is a well-known maladaptive strategy that is related with diverse psychological problems such as negative affect and depression [32,75,76], as well as with several factors related to those like lower interpersonal functioning, well-being, life satisfaction, self-esteem, optimism and emotional intelligence [32]. In this line, the higher use of maladaptive emotion regulation strategies, like expressive suppression, and the lower use of adaptive ones, as cognitive reappraisal, observed for those people closer to the eveningness pole reinforces the assumption of the evening-type as a risk factor for the development of psychological problems and pathologies.

Regarding metacognitions, the hypothesis that evening-type participants show the highest tendency to suffer maladaptive cognitions about the thinking is supported by the results, while neither-type subjects tendency is between both extreme groups. Concretely, it was observed that evening-type subjects showed the highest tendency to show negative beliefs about uncontrollability and danger (“worry is uncontrollable” or “my worry is dangerous for me”), to distrust own cognitive memory (“I do not trust my memory” or “my memory can mislead me at times”), and to monitor the attention to one’s thoughts (“I think a lot about my thoughts” or “I am constantly aware of my thinking”). In this line, and according to the regression results, the closer one is to the eveningness pole, the higher the tendency is to suffer more maladaptive metacognitions, specifically worries about worrying, distrust own memory, monitor thoughts, and feel the need to control thoughts. Moreover, in line with the results of the Spanish adaptation of the MCQ-30 [62] men showed the highest tendency to suffer maladaptive thinking about own cognitions such as positive beliefs about worry (“worry helps me to solve problems or to work well”) and need to control thoughts (“it is bad to think certain thoughts” or “not being able to control my thoughts is a sign of weakness”), as well as the lowest cognitive confidence. Nevertheless, the non-interaction observed between sex and circadian typology indicates that circadian typology results are independent of sex.

The higher tendency to hold negative beliefs of uncontrollability and danger, to distrust the own memory and to stay continuously aware of self-thinking observed in evening-type supports the assumption of this typology as a risk factor for the development of different psychological problems and pathologies [9,11], as these metacognitive beliefs are related to diverse problems such as drug consumption and addictive behaviors [47,77,78], anxiety and stress [45,46,79] and depressive symptomatology [41,80,81], among others.

The assertiveness results support the hypothesis of a greater tendency to affirm a right or a point of view without either aggressively threatening the rights of another nor submissively allow another to deny one’s rights or point of view in the morning-type, which contrasts with the lower ability in the evening-type, while neither-type individuals are in an intermediate position. Likewise, according to the regression results, it was also found that the morningness-eveningness dimension was directly related with this ability. Moreover, and in line with previous results [82], the absence of sex differences for this skill suggests that obtained results are independent of sex.

Assertiveness constitutes a core skill for well-being which is positively implied in happiness [58], self-esteem [54] and relationship satisfaction [56], as well as in the amelioration of diverse psychological disturbances [51]. Thus, the higher capacity to affirm a right respectfully observed in the morning-type is in line with the consideration of this circadian typology as a protective factor against the development of psychological issues. Likewise, low assertiveness has been found related with psychological problems like depression [52], anxiety [50,53] and major mental problems [55], issues that are more prone in evening-type, reinforcing the consideration of this chronotype as a risk factor for those.

Altogether, although there was some sex differences observed for the emotion regulation strategies and metacognitions, the absence of interactive effects between sex and circadian typology suggests that obtained results for emotion regulation strategies, metacognitions and assertiveness results could provide additional evidence for a better understanding of the relationship between circadian typology and psychological characteristics which might underlie their associations with psychological problem and strengths. Likewise, it must be noted that differences found between evening and morning-type participants remain significant even once age and sex are removed from the model. Results might be explained by the social jet lag theory [16], which hypothesizes that the social jet-lag sufferers, mainly evening-type, must set up strategies in order to adapt to or to mitigate the misalignment between their biological and the social clock, which is commonly oriented towards morningness. In this line, evening-type persons, who are the mainly social jet-lag sufferers, must perform different functions (sleep and wake-up, eat, work, study, child care, etc.) in a schedule that is unadjusted to their biological clock, which might be understood as upstream swim, that might result in higher fatigue as it has been observed in previous works [83-85]. In this line, longitudinal studies are needed to analyze if this worse emotion regulation strategies together with the maladaptive metacognitive style and the lower assertiveness observed in those participants closer to the eveningness pole might be the result of this higher fatigue.

This study is not exempt of limitations. One of them is the low control of the on-line data collection as compared with traditional paper questionnaires. Moreover, the presence of psychological and medical problems, which was assessed by self-report questions and not by physical and psychological or psychiatric interviews constitute a weakness. Age and sex proportions of the sample are also limitations. In this line, there was a wide proportion of participants aged 20–30, which differs from Spanish population normative data and that might be attributed to the way the study was spread (university and social networks mainly). Likewise, the higher proportion of men can be also considered as a weakness. Finally, regression results, although significant, are relatively low, implying that conclusions derived from those should be made cautiously.

Summarizing, this is the first study which assesses the associations between circadian typology, emotion regulation strategies, metacognitions and assertiveness in a wide sample of healthy adults. Morning-type participants showed the higher use of cognitive reappraisal, the higher assertiveness and the lower amount maladaptive metacognitions while evening-type showed the lower use of cognitive reappraisal, the lower assertiveness and the higher amount maladaptive metacognitions, while the neither-type participants hold an intermediate position between the extreme groups. The results emphasize that circadian typology is related to psychological well-being in healthy population, highlighting the assumption of the morning-type as a protective factor against the development of psychological issues as well as the consideration of the evening-type as a risk factor for the development of diverse problems like depression, anxiety and substance use. Likewise, obtained results may improve the understanding of the associations between circadian typology and different psychological factors related to well-being and psychological health and psychopathology by offering possible explanations of their relationships. In addition, the results may become useful for healthcare professional, mostly psychologists, that should take into account the circadian typology and the social jet-lag when developing meta-cognitive therapy and psychotherapeutic processes orientated to improving the emotion regulation strategies and assertiveness, as well as for the development of prevention and health promotion programs. Further research, mainly longitudinal, is needed for a better understanding of the relationships between circadian typology and emotion regulation, metacognitions and assertiveness.

30 Oct 2019

PONE-D-19-23969

Circadian typology is related to emotion regulation, metacognitive beliefs and assertiveness in healthy adults

PLOS ONE

Dear Dr. Antúnez,

Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process.

I have been able to secure useful feedback from one Reviewer. Please, see the specific comments at the bottom of this letter. I would not repeat these comments here. This evaluation of your manuscript highlights that there were several major concerns with the current version of the study. These concerns could be addressed in a reviewed version of your study.

However, because this may be considered as a major review, please notice that a resubmission will require another round of reviews, hopefully from more that just one Reviewer, and that the final outcome of this process cannot be predicted at this point. If you decide to resubmit, please address each of the concerns that were reaised in the current review.

We would appreciate receiving your revised manuscript by Dec 13 2019 11:59PM. When you are ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file.

If you would like to make changes to your financial disclosure, please include your updated statement in your cover letter.

To enhance the reproducibility of your results, we recommend that if applicable you deposit your laboratory protocols in protocols.io, where a protocol can be assigned its own identifier (DOI) such that it can be cited independently in the future. For instructions see: http://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols

Please include the following items when submitting your revised manuscript:

A rebuttal letter that responds to each point raised by the academic editor and reviewer(s). This letter should be uploaded as separate file and labeled 'Response to Reviewers'.

A marked-up copy of your manuscript that highlights changes made to the original version. This file should be uploaded as separate file and labeled 'Revised Manuscript with Track Changes'.

An unmarked version of your revised paper without tracked changes. This file should be uploaded as separate file and labeled 'Manuscript'.

Please note while forming your response, if your article is accepted, you may have the opportunity to make the peer review history publicly available. The record will include editor decision letters (with reviews) and your responses to reviewer comments. If eligible, we will contact you to opt in or out.

We look forward to receiving your revised manuscript.

Kind regards,

Angel Blanch, Ph.D.

Academic Editor

PLOS ONE

Journal Requirements:

1.

When submitting your revision, we need you to address these additional requirements.

Please ensure that your manuscript meets PLOS ONE's style requirements, including those for file naming. The PLOS ONE style templates can be found at

http://www.journals.plos.org/plosone/s/file?id=wjVg/PLOSOne_formatting_sample_main_body.pdf and http://www.journals.plos.org/plosone/s/file?id=ba62/PLOSOne_formatting_sample_title_authors_affiliations.pdf

2.  We noticed you have some minor occurrence of overlapping text with the following previous publication(s), which needs to be addressed:

https://www.tandfonline.com/doi/abs/10.3109/07420528.2015.1008700?journalCode=icbi20

In your revision ensure you cite all your sources (including your own works), and quote or rephrase any duplicated text outside the methods section. Further consideration is dependent on these concerns being addressed.

[Note: HTML markup is below. Please do not edit.]

Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: Yes

**********

2. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: I Don't Know

**********

3. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: Yes

**********

4. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: No

**********

5. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: PONE-D-19-02089

Title: Circadian typology is related to emotion regulation, metacognitive beliefs and

assertiveness in healthy adults

In his manuscript entitled “Circadian typology is related to emotion regulation, metacognitive beliefs and assertiveness in healthy adults”, J.M. Antúnez addresses potential associations between self-reported circadian preference (evening vs. morning types) and several other personality-related traits (as indexed by questionnaire measures), providing partial support for the hypothesis of higher prevalence of dysfunctional beliefs/strategies in individuals reporting a subjective bias toward later circadian phases.

Overall, this is an interesting paper based on a large-sample study with considerable relevance to the field. However, I have several concerns with respect to some methodological issues as well as the interpretations of findings and final conclusions drawn by the author (as outlined in more detail below).

Moreover, throughout the manuscript (starting with the first sentence) there are many instances of awkward language, regarding both non-idiomatic style (i.e., choice of words) and grammatical errors (mostly minor aberrations, such as lack of 3rd person “-s”, e.g., yet sometimes more severe cases, such as incomplete sentences). The text should therefore be thoroughly proofread by a native speaker before final acceptance for publication can be considered.

In a similar vein, use of references styles is not entirely consistent across the manuscript (e.g., full author references on p. 6).

Apart from some problems with grammar and phrasing (see above), both Abstract and Introduction are well-written and clear in stating the present study’s background and main objectives.

The description of the methods is straightforward and clear. (Minor issue: There seems to be a misplaced decimal marker in the description of the internal consistency of the ERQ scales.)

The Results section is also largely consistent. However, it is unclear how exactly post-hoc testing was performed: What do the numbers in brackets indicate (t-values, F-values …)? (Minor issue: There is probably a wrong “>” symbol on p. 10.)

Moreover: How do the results look like when age and sex are not entered as predictors (in ANCOVA or multiple regression, respectively)? Are the differences between evening and morning type still significant? Most importantly: Is the increase in explained variance (incremental variance) by inclusion of the rMEQ scores, as described on pp. 13-14, significant? The author should include this important information and also consider reporting all respective regression weights for each model.

If the finding of an association of circadian typology and other traits depends on statistical control for age and sex (as I am inclined to suspect on the basis of the information provided), this should be highlighted and clearly addressed as a limitation in the Discussion. Also, given that the results are based purely on self-report as well as a correlational design without longitudinal assessment, I would strongly recommend phrasing the conclusions in a much more cautious way, since neither is there direct evidence for the alleged association between psychopathology and circadian typology (discussed as a “risk factor” by the author) nor is there any indication of a direct causal link between circadian typology and emotion regulation (i.e., the design of the study is not at all appropriate for elucidating the direction of causation at all).

Taken together, most of my concerns may be addressed in a thorough revision of the manuscript. Therefore, this could become an interesting and valuable contribution to the literature, given that the manuscript would have been proofread and corrected with respect to grammar and style, the conclusions would be expressed in a more cautious way, and the shortcomings of the study (as described above) would be explicitly addressed.

**********

6. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files.

If you choose “no”, your identity will remain anonymous but your review may still be made public.

Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy.

Reviewer #1: No

[NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files to be viewed.]

While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, https://pacev2.apexcovantage.com/. PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email us at figures@plos.org. Please note that Supporting Information files do not need this step.

28 Nov 2019

Dear Prof Blanch,

Thank you for giving me the opportunity to revise my work for your further consideration. I have considered all the points that have been required by the journal and suggested by the reviewer which has allowed me to improve the manuscript. Next, I reply to each of the comments in a detailed and itemized form.

Journal requirements:

1. Please ensure that your manuscript meets PLOS ONE’s style requirements, including those for file naming.

Attending to your requirement, manuscript meets PLOS ONE’s style requirements.

2. We noticed you have some minor occurrence of overlapping text with the following previous publication, which needs to be addressed: https://www.tandfondline.com/doi/abs/10.3109/07420528.215.1008700?journalCode=icbi20 In your revision ensure you cite all your sources (including your own works), and quote or rephrase any duplicated text outside the methods section.

Regarding your requirement, minor overlapping text with other previous publications has been edited.

Reviewer comments:

1. Moreover, throughout the manuscript (starting with the first sentence) there are many instances of awkward language, regarding both non-idiomatic style (i.e., choice of words) and grammatical errors (mostly minor aberrations, such as lack of 3rd person “-s”, e.g., yet sometimes more severe cases, such as incomplete sentences). The text should therefore be thoroughly proofread by a native speaker before final acceptance for publication can be considered.

Regarding your suggestion, the manuscript has been proofread by a native speaker.

2. In a similar vein, use of references styles is not entirely consistent across the manuscript (e.g., full author references on p. 6).

Attending to your comment, all references have been revised to ensure the style consistency across the manuscript.

3. There seems to be a misplaced decimal marker in the description of the internal consistency of the ERQ scales.

Regarding your comment, misplaced decimal marker in the description of the internal consistency of the ERQ scales has been corrected.

4. The Results section is also largely consistent. However, it is unclear how exactly post-hoc testing was performed: What do the numbers in brackets indicate (t-values, F-values …)?

Attending to your recommendation, brackets that indicate mean differences (MD) have been modified so every reader will understand its meaning.

5. (Minor issue: There is probably a wrong “>” symbol on p. 10.)

Regarding your comment, the wrong “>” symbol on p. 10 has been modified to “<”.

6. Moreover: How do the results look like when age and sex are not entered as predictors (in ANCOVA or multiple regression, respectively)? Are the differences between evening and morning type still significant? Most importantly: Is the increase in explained variance (incremental variance) by inclusion of the rMEQ scores, as described on pp. 13-14, significant? The author should include this important information and also consider reporting all respective regression weights for each model.

ANCOVA and MANCOVA analyses without age and sex as independent and covariate respectively have a considerable impact in the results as F-scores for every variable, except for cognitive confidence, were increased (even positive beliefs difference between morning and evening-types become significant with this change). In the case of cognitive confidence, F-score decreased but group differences remained significant.

Regarding regression analyses, the non-inclusion of age and sex as predictors showed significant results for every variable: Cognitive reappraisal (R2 = .005, F = 12.21, p < .001), Expressive suppression (R2 = .016, F = 37.90, p < .001), assertiveness (R2 = .007, F = 18.08, p < .001), MCQ-30 total score (R2 = .021, F = 49.45, p < .001), positive beliefs about worry (R2 = .004, F = 10.03, p = .002), negative beliefs of uncontrollability and danger (R2 = .010, F = 24.81, p < .001), cognitive confidence (R2 = .003, F = 8.56, p = .003), need to control thoughts (R2 = .013, F = 31.44, p < .001) and self-consciousness (R2 = .022, F = 51.84, p < .001).

Moreover, attending to your recommendation, the increase in explained variance significance has been included in the manuscript.

Age and sex were included as factor and covariate respectively to make circadian typology results more accurate. That is because circadian typology is clearly related to age while sex has been found related to diverse variables such as suppress expression, and these relations might affect the results. The aim of the study was to analyze the relationship between circadian typology and metacognitions, emotion regulation and assertiveness, by controlling and neutralizing two factors (age and sex) that may underlie several associations and boost our results unless those were controlled.

Regarding your recommendation, regression coefficients (B, SE B and β) for each model were reported in Tables 4 and 5.

7. If the finding of an association of circadian typology and other traits depends on statistical control for age and sex (as I am inclined to suspect on the basis of the information provided), this should be highlighted and clearly addressed as a limitation in the Discussion.

Associations between circadian typology and other traits did not depend on statistical control for age and sex. Moreover, the exclusion of sex and age as controlled variables resulted in higher weight on the associations.

8. Also, given that the results are based purely on self-report as well as a correlational design without longitudinal assessment, I would strongly recommend phrasing the conclusions in a much more cautious way, since neither is there direct evidence for the alleged association between psychopathology and circadian typology (discussed as a “risk factor” by the author) nor is there any indication of a direct causal link between circadian typology and emotion regulation (i.e., the design of the study is not at all appropriate for elucidating the direction of causation at all).

Attending to your recommendation, conclusions have been re-phrased in a much more cautious way, avoiding any term that may suggest any direct causal link between circadian typology and any one of the studied traits nor direct evidence for the alleged association between psychopathology and circadian typology:

“Altogether, although there was some sex differences observed for the emotion regulation strategies and metacognitions, the absence of interactive effects between sex and circadian typology suggests that obtained results for emotion regulation strategies, metacognitions and assertiveness results could provide additional evidence for a better understanding of the relationship between circadian typology and psychological characteristics which might underlie their associations with psychological problem and strengths. Results might be explained by the social jet lag theory [16], which hypothesizes that the social jet-lag sufferers, mainly evening-type, must set up strategies in order to adapt to or to mitigate the misalignment between their biological and the social clock, which is commonly oriented towards morningness. In this line, evening-type persons, who are the mainly social jet-lag sufferers, must perform different functions (sleep and wake-up, eat, work, study, child care, etc.) in a schedule that is unadjusted to their biological clock, which might be understood as upstream swim, leading to a widespread fatigue for cognitive, emotional and behavioral systems. In this line, longitudinal studies are needed to analyze if this worse emotion regulation strategies together with the maladaptive metacognitive style and the lower assertiveness observed in those participants closer to the eveningness pole might be the result of this higher fatigue.”

Submitted filename: Response to Reviewers.docx

Click here for additional data file.

3 Feb 2020

PONE-D-19-23969R1

Circadian typology is related to emotion regulation, metacognitive beliefs and assertiveness in healthy adults

PLOS ONE

Dear Dr. Antúnez,

Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process.

This version of the manuscript has been evaluated by Reviewer #1, who provided initial feedback about your study in the previous round of reviews. In addition, there are additional comments from a new Reviewer (#2). Please, see their comments at the bottom of this letter. As you will see, there is still room for further improving the presentation of your study. Therefore, the manuscript should be reviewed again in accordance with these latter suggestions.

We would appreciate receiving your revised manuscript by Mar 19 2020 11:59PM. When you are ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file.

If you would like to make changes to your financial disclosure, please include your updated statement in your cover letter.

To enhance the reproducibility of your results, we recommend that if applicable you deposit your laboratory protocols in protocols.io, where a protocol can be assigned its own identifier (DOI) such that it can be cited independently in the future. For instructions see: http://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols

Please include the following items when submitting your revised manuscript:

A rebuttal letter that responds to each point raised by the academic editor and reviewer(s). This letter should be uploaded as separate file and labeled 'Response to Reviewers'.

A marked-up copy of your manuscript that highlights changes made to the original version. This file should be uploaded as separate file and labeled 'Revised Manuscript with Track Changes'.

An unmarked version of your revised paper without tracked changes. This file should be uploaded as separate file and labeled 'Manuscript'.

Please note while forming your response, if your article is accepted, you may have the opportunity to make the peer review history publicly available. The record will include editor decision letters (with reviews) and your responses to reviewer comments. If eligible, we will contact you to opt in or out.

We look forward to receiving your revised manuscript.

Kind regards,

Angel Blanch, Ph.D.

Academic Editor

PLOS ONE

[Note: HTML markup is below. Please do not edit.]

Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation.

Reviewer #1: (No Response)

Reviewer #2: (No Response)

**********

2. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: Yes

Reviewer #2: Partly

**********

3. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: Yes

Reviewer #2: Yes

**********

4. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: Yes

Reviewer #2: Yes

**********

5. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: Yes

Reviewer #2: No

**********

6. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: After a second, thorough reading I conclude that all of my concerns have been sufficiently addressed and the quality of the paper has improved considerably.

I appreciate the author’s methodological scrutiny in controlling for potential confounding variables. (i.e., age and sex). However, the author should add a sentence or two (e.g., in the Discussion) asserting to the reader that the differences between evening and morning type are still significant even if age and sex are left out of the model.

Minor: Typo “lineal regression” in headings of Tables 4 and 5.

Reviewer #2: The author presents the results of an online study about the link between morningness-eveningness (circadian typology) and adaptive or maladaptive habits in emotion regulation, metacognitive beliefs and assertiveness. I think the manuscript is well suited for publication in PLOSone but still needs some adjustments.

Major aspects:

“Likewise, significant differences were observed between women (14.78 ± 0.15) and men (13.67 ± 0.11) in rMEQ scores (t(1,2281) = 5.89, p < 0.001, Cohen’s d = 0.25).” Does this mean that more women are morning types?

Related to that how does this match with the statements: “Nevertheless, the absence of interactive effect between sex and circadian typology suggests that the circadian typology obtained results are independent of sex.”and “Nevertheless, the non-interaction observed between sex and circadian typology indicates that circadian typology results are independent of sex”

Isn’t the interesting aspect here that morningness-eveningness can contribute to the explanation of emotion regulation, metacognitive beliefs and assertiveness beyond sex as revealed by the regression analysis?

The author writes “Participants distribution according to the morningness- eveningness dimension was skewed toward eveningness, which is in line with previous studies performed with large samples [3,4].” Does this mean that we are facing a representative sample here? Further comparisons might be useful. What about the mentioned usual distribution of 20/60/20 % of morning/indifferent/evening types – is this found within the sample?

When fatigue is discussed I was wondering whether there is any evidence yet that supports this idea, that evening-types suffer from fatigue? If I got the reasoning right that is deduced from social jet-lag theory evening-types (working against their biological clock) that have to adapt to a more morning-oriented social clock should experience greater fatigue which brings up maladaptive cognitive, emotional and behavioral habits. What about other groups of persons or cultures?

Minor aspects:

I think the english language still needs some corrections e.g. “…non-found…”; “…the hypothesis that evening-type participants show(s)…”; “One of them is the lower absence of control of the on-line data collection…”

I was wondering how many participants were excluded due to duplicate answers and how many because they did not meet the inclusion criteria. Also the inclusion/exclusion criteria should be named half a page earlier when the exclusion is mentioned. Does inclusion/exclusion significantly change the results of the present study?

Please explain the score range for the rMEQ. What are the scales?

Decimal separators are inkonsistent in the participants section and in Table 1.

“…and evening-type (27.49 ± 0.30 yrs; p < 0.001), who were older than neither-type (p < 0.001).” I believe it should read younger, if the the numbers are in brackets are means.

The metacognitions sections would be easier to follow when all post-hoc comparisons would follow the description of significance directly.

I think the section regression analysis is not easy to follow linguistically as links are not clear. Also: was the increase from the first to the second model significant?

Table 2 should be ordered the same way as the results section.

Table 4 und 5 are named alike. Aren’t the information in Table 5 subscales of metacognitive beliefs?

Please provide english explanations for the variables in the .sav-file on OSF.

**********

7. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files.

If you choose “no”, your identity will remain anonymous but your review may still be made public.

Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy.

Reviewer #1: No

Reviewer #2: No

[NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files to be viewed.]

While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, https://pacev2.apexcovantage.com/. PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email us at figures@plos.org. Please note that Supporting Information files do not need this step.

12 Feb 2020

Reviewer #1:

1. The author should add a sentence or two (e.g., in the Discussion) asserting to the reader that the differences between evening and morning type are still significant even if age and sex are left out of the model.

Regarding your suggestion, the assertion that the differences between evening- and morning-type are still significant even if age and sex are left out of the model has been added to the discussion:

“Likewise, it must be noted that differences found between evening and morning-type participants remain significant even once age and sex are removed from the model.”

2. Minor: Typo “lineal regression” in headings of Tables 4 and 5.

According to your correction, “lineal regression” has been modified to “linear regression” in both headings of Tables 4 and 5.

Reviewer #2:

1. “Likewise, significant differences were observed between women (14.78 ± 0.15) and men (13.67 ± 0.11) in rMEQ scores (t(1,2281) = 5.89, p < 0.001, Cohen’s d = 0.25).” Does this mean that more women are morning types?

Not really, it is needed a score between 18 and 25 in rMEQ to be considered as a morning-type. Nevertheless, it can be said that women are more morning-type than men.

2. Related to that how does this match with the statements: “Nevertheless, the absence of interactive effect between sex and circadian typology suggests that the circadian typology obtained results are independent of sex.”and “Nevertheless, the non-interaction observed between sex and circadian typology indicates that circadian typology results are independent of sex”. Isn’t the interesting aspect here that morningness-eveningness can contribute to the explanation of emotion regulation, metacognitive beliefs and assertiveness beyond sex as revealed by the regression analysis?

Absolutely. Both statements are not incompatible with the greater tendency in women toward morningness. Despite this result, no interactive effect between sex and circadian typology in ANCOVA and MANCOVA analyses was found for any of the assessed variables. In other words, although sex exerted an important influence in some variables, carried out analyses revealed that circadian typology was also clearly related to the studied variables regardless of sex, as it has been shown in regression analyses.

3. The author writes “Participants distribution according to the morningness- eveningness dimension was skewed toward eveningness, which is in line with previous studies performed with large samples [3,4].” Does this mean that we are facing a representative sample here? Further comparisons might be useful. What about the mentioned usual distribution of 20/60/20 % of morning/indifferent/evening types – is this found within the sample?

The present sample comprised a 27.9% of evening-type, 48.8% of neither-type, and 23.3% of morning-type participants. I assume that the 27.9% rate of evening-type participants might be due to the wide proportion of participants aged 20-30, that differs from the European population (where the wider proportion rounds 35-60 years according to eurostat).

4. When fatigue is discussed I was wondering whether there is any evidence yet that supports this idea, that evening-types suffer from fatigue?

Different studies have observed a higher fatigue among evening-type (Fárková, Šmotek, Bendová, Manková, & Kopřivová, 2019; Furusawa et al., 2015; Jeon, Bang, Park, Kim, & Yoon, 2017) . Taking your comment into account, those references have been added to the text. Moreover, as this study did not analyze the fatigue and cause-effect, the fatigue-related phrase has been modified:

“In this line, evening-type persons, who are the mainly social jet-lag sufferers, must perform different functions (sleep and wake-up, eat, work, study, child care, etc.) in a schedule that is unadjusted to their biological clock, which might be understood as upstream swim, that might result in higher fatigue as it has been observed in previous works [83-85].”

5. If I got the reasoning right that is deduced from social jet-lag theory evening-types (working against their biological clock) that have to adapt to a more morning-oriented social clock should experience greater fatigue which brings up maladaptive cognitive, emotional and behavioral habits. What about other groups of persons or cultures?

It will always depends on the synchrony between the social (cultural) clock and the biological clock of any individual.

6. I think the english language still needs some corrections e.g. “…non-found…”; “…the hypothesis that evening-type participants show(s)…”; “One of them is the lower absence of control of the on-line data collection…

Attending to your comment, corrections have been performed.

7. I was wondering how many participants were excluded due to duplicate answers and how many because they did not meet the inclusion criteria.

Fifty-one duplicate answers were found. First, data was introduced into a Microsoft Excel sheet and a function that highlights all duplicate rows was performed. Second, the absence of very similar responses was checked manually. For this purpose, I checked responses that were sent almost simultaneously. Finally, email duplicates were looked for. For those, the similarity of the replies to the different questionnaires, specially to sociodemographic data, was checked. In the event that sociodemographic data were different, this was not considered as a duplicate answer.

8. Also the inclusion/exclusion criteria should be named half a page earlier when the exclusion is mentioned.

According to your recommendation, inclusion/exclusion criteria has been named following the exclusion mention:

“The total amount of participants in the study was 3016, out of which 733 were excluded due to duplicate answers and for non-accomplishing the inclusion criteria (Spanish resident, absence of mental and physical health problems, absence of shift work and 18-60 yrs).”

9. Does inclusion/exclusion significantly change the results of the present study?

Yes. If exclusion criteria are not applied the obtained results are stronger in terms of new significant associations as well as in term of statistical results (p, R2, F, partial eta square and observed power).

10. Please explain the score range for the rMEQ. What are the scales?

rMEQ is a 25-items questionnaire that can be scored between 4 and 25. The lower the scores are, the closer one is to the eveningness pole; The higher the scores are, the closer one is to the morningness pole. Moreover, this questionnaire allows to classify participants into three circadian typology categories: evening-type (for scores between 4 and 11), neither-type (for scores between 12 and 17), and morning-type (for scores between 18 and 25).

11. Decimal separators are inkonsistent in the participants section and in Table 1.

Attending to your comment, decimals separators in participants section and in Table 1 have been corrected.

12. “…and evening-type (27.49 ± 0.30 yrs; p < 0.001), who were older than neither-type (p < 0.001).” I believe it should read younger, if the the numbers are in brackets are means.

Attending to your correction, older has been changed to younger.

13. The metacognitions sections would be easier to follow when all post-hoc comparisons would follow the description of significance directly.

Attending to your recommendation, metacognitions section has been modified as follows:

“Significant main effects were observed in MCQ-30 total score, negative beliefs of uncontrollability and danger, cognitive confidence and cognitive self-consciousness for circadian typology. According to post-hoc comparisons, neither-type participants showed higher scores than morning-type in cognitive confidence (MD = 0.70, p = 0.012, Cohen’s d = 0.12) and scored lower than evening-type in MCQ-30 total score (MD = 1.94, p = 0.032, Cohen’s d = 0.21) and cognitive self-consciousness (MD = 0.65, p = 0.016, Cohen’s d = 0.23). Evening-type subjects showed higher scores than morning-type in MCQ-30 total score (MD = 3.13, p = 0.002, Cohen’s d = 0.17), negative beliefs of uncontrollability and danger (MD = 0.91, p = 0.002, Cohen’s d = 0.23), cognitive confidence (MD = 0.97, p = 0.002, Cohen’s d = 0.17) and cognitive self-consciousness (MD = 0.74, p = 0.02, Cohen’s d = 0.39).Regarding sex, significant main effects were observed in positive beliefs about worry, need to control thoughts and cognitive self-consciousness. In this line, men scored higher than women in positive beliefs about worry (MD = 1.27, p > .001, Cohen’s d = 0.35), need to control thoughts (MD = 1.29, p > .001, Cohen’s d = 0.38) and cognitive self-consciousness (MD = 0.74, p > .001, Cohen’s d = 0.23).”

14. I think the section regression analysis is not easy to follow linguistically as links are not clear.

Attending to your recommendation, regression section has been modified as follows:

“Table 3 shows results of multiple regression analyses while Tables 4 and 5 show the model coefficients for each variable. The analyses revealed that sex and age were significantly related to cognitive reappraisal (explaining a 0.4% of the variance), expressive suppression (14.2%), assertiveness (0.7%), metacognitions (3.9%), positive beliefs about worry (5.2%), need to control thoughts (5.5%) and cognitive self-consciousness (6.6%), with p < .05 in all cases. Moreover, the inclusion of the rMEQ scores in the equation significantly increased the explained variance for cognitive reappraisal (0.5%), expressive suppression (0.3%), assertiveness (0.6%), metacognitions (0.8%), negative beliefs of uncontrollability and danger (0.9%), cognitive confidence (0.7%), need to control thoughts (0.3%) and cognitive self-consciousness (0.5%), with p < .05 in all cases.”

15. Also: was the increase from the first to the second model significant?

Significant increases from the first to the second model was observed for cognitive reappraisal, expressive suppression, assertiveness, metacognitions, negative beliefs of uncontrollability and danger, cognitive confidence, need to control thoughts and cognitive self-consciousness. Regarding your comment, the fact that the inclusion of the rMEQ scores in the equation resulted in a significantly increase of the explained variance was added to this section:

“Moreover, the inclusion of the rMEQ scores in the equation resulted in a significantly increase of the explained variance for cognitive reappraisal…”

16. Table 2 should be ordered the same way as the results section.

According to your recommendation, Table 2 has been ordered the same way as the results section

17. Table 4 und 5 are named alike. Aren’t the information in Table 5 subscales of metacognitive beliefs?

Attending to your comment, tables 4 and 5 have been renamed as follows:

“Table 4. Multiple linear regression model coefficients for emotion regulation strategies, assertiveness and MCQ-30 total score.”

“Table 5. Multiple linear regression model coefficients for the different metacognitions assessed through MCQ-30.”

18. Please provide english explanations for the variables in the .sav-file on OSF.

The file with English explanations for the variables can be found at https://osf.io/nh5c4

Submitted filename: Response to reviewers.docx

Click here for additional data file.

25 Feb 2020

Circadian typology is related to emotion regulation, metacognitive beliefs and assertiveness in healthy adults

PONE-D-19-23969R2

Dear Dr. Antúnez,

We are pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it complies with all outstanding technical requirements.

Within one week, you will receive an e-mail containing information on the amendments required prior to publication. When all required modifications have been addressed, you will receive a formal acceptance letter and your manuscript will proceed to our production department and be scheduled for publication.

Shortly after the formal acceptance letter is sent, an invoice for payment will follow. To ensure an efficient production and billing process, please log into Editorial Manager at https://www.editorialmanager.com/pone/, click the "Update My Information" link at the top of the page, and update your user information. If you have any billing related questions, please contact our Author Billing department directly at authorbilling@plos.org.

If your institution or institutions have a press office, please notify them about your upcoming paper to enable them to help maximize its impact. If they will be preparing press materials for this manuscript, you must inform our press team as soon as possible and no later than 48 hours after receiving the formal acceptance. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information, please contact onepress@plos.org.

With kind regards,

Angel Blanch, Ph.D.

Academic Editor

PLOS ONE

Additional Editor Comments (optional):

Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation.

Reviewer #1: All comments have been addressed

**********

2. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: Yes

**********

3. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: Yes

**********

4. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: Yes

**********

5. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: Yes

**********

6. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: (No Response)

**********

7. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files.

If you choose “no”, your identity will remain anonymous but your review may still be made public.

Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy.

Reviewer #1: No

2 Mar 2020

PONE-D-19-23969R2

Circadian typology is related to emotion regulation, metacognitive beliefs and assertiveness in healthy adults

Dear Dr. Antúnez:

I am pleased to inform you that your manuscript has been deemed suitable for publication in PLOS ONE. Congratulations! Your manuscript is now with our production department.

If your institution or institutions have a press office, please notify them about your upcoming paper at this point, to enable them to help maximize its impact. If they will be preparing press materials for this manuscript, please inform our press team within the next 48 hours. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information please contact onepress@plos.org.

For any other questions or concerns, please email plosone@plos.org.

Thank you for submitting your work to PLOS ONE.

With kind regards,

PLOS ONE Editorial Office Staff

on behalf of

Dr. Angel Blanch

Academic Editor

PLOS ONE