OBJECTIVES: The fall in the prevalence of left handedness with age has been attributed to either premature mortality or a cohort effect of forced dextrality. Evidence for forced dextrality was sought to differentiate between these competing theories. DESIGN: 6097 Edinburgh handedness inventories were used to calculate laterality quotients (LQ) with and without the questions relating to writing and drawing. These questions might be expected to be most influenced by forced dextrality. SETTING: The study was performed in a small industrial town in Lancashire, UK. PARTICIPANTS: Using the British family practitioner service where over 95% of the population are registered with a general practitioner a response rate of 82.17% was obtained with respect to the Edinburgh Inventory. RESULTS: Questions about writing and drawing on the Edinburgh Inventory contributed to the positivity (right handedness) of the mean LQ, but equally across the ages. When a negative LQ was used to define left handedness the prevalence of left handedness fell from 11.2% at age 15 to 4.4% at age 70. Removal of the questions about writing and drawing caused the prevalence of left handedness to fall from 10.5% at age 15 to 4.95% at age 70. CONCLUSIONS: Less than 20% of the fall in the prevalence of left handedness was accounted for by questions relating to writing and drawing. The fall in the prevalence of sinistrals in older age groups is not adequately explained by cohort effects of forced dextrality on the writing hand.
OBJECTIVES: The fall in the prevalence of left handedness with age has been attributed to either premature mortality or a cohort effect of forced dextrality. Evidence for forced dextrality was sought to differentiate between these competing theories. DESIGN: 6097 Edinburgh handedness inventories were used to calculate laterality quotients (LQ) with and without the questions relating to writing and drawing. These questions might be expected to be most influenced by forced dextrality. SETTING: The study was performed in a small industrial town in Lancashire, UK. PARTICIPANTS: Using the British family practitioner service where over 95% of the population are registered with a general practitioner a response rate of 82.17% was obtained with respect to the Edinburgh Inventory. RESULTS: Questions about writing and drawing on the Edinburgh Inventory contributed to the positivity (right handedness) of the mean LQ, but equally across the ages. When a negative LQ was used to define left handedness the prevalence of left handedness fell from 11.2% at age 15 to 4.4% at age 70. Removal of the questions about writing and drawing caused the prevalence of left handedness to fall from 10.5% at age 15 to 4.95% at age 70. CONCLUSIONS: Less than 20% of the fall in the prevalence of left handedness was accounted for by questions relating to writing and drawing. The fall in the prevalence of sinistrals in older age groups is not adequately explained by cohort effects of forced dextrality on the writing hand.
Authors: Hui-Chun Tsuang; Chih-Min Liu; Tzung J Hwang; Ming H Hsieh; Stephen V Faraone; Ming T Tsuang; Hai-Gwo Hwu; Wei J Chen Journal: Laterality Date: 2011-06-24
Authors: David Bergeron; Maria L Gorno-Tempini; Gil D Rabinovici; Miguel A Santos-Santos; William Seeley; Bruce L Miller; Yolande Pijnenburg; M Antoinette Keulen; Colin Groot; Bart N M van Berckel; Wiesje M van der Flier; Philip Scheltens; Jonathan D Rohrer; Jason D Warren; Jonathan M Schott; Nick C Fox; Raquel Sanchez-Valle; Oriol Grau-Rivera; Ellen Gelpi; Harro Seelaar; Janne M Papma; John C van Swieten; John R Hodges; Cristian E Leyton; Olivier Piguet; Emily J Rogalski; Marsel M Mesulam; Lejla Koric; Kristensen Nora; Jeéreémie Pariente; Bradford Dickerson; Ian R Mackenzie; Ging-Yuek R Hsiung; Serge Belliard; David J Irwin; David A Wolk; Murray Grossman; Matthew Jones; Jennifer Harris; David Mann; Julie S Snowden; Patricio Chrem-Mendez; Ismael L Calandri; Alejandra A Amengual; Carole Miguet-Alfonsi; Eloi Magnin; Giuseppe Magnani; Roberto Santangelo; Vincent Deramecourt; Florence Pasquier; Niklas Mattsson; Christer Nilsson; Oskar Hansson; Julia Keith; Mario Masellis; Sandra E Black; Jordi A Matías-Guiu; María-Nieves Cabrera-Martin; Claire Paquet; Julien Dumurgier; Marc Teichmann; Marie Sarazin; Michel Bottlaender; Bruno Dubois; Christopher C Rowe; Victor L Villemagne; Rik Vandenberghe; Elias Granadillo; Edmond Teng; Mario Mendez; Philipp T Meyer; Lars Frings; Alberto Lleó; Rafael Blesa; Juan Fortea; Sang Won Seo; Janine Diehl-Schmid; Timo Grimmer; Kristian Steen Frederiksen; Pascual Sánchez-Juan; Gaël Chételat; Willemijn Jansen; Rémi W Bouchard; Robert Jr Laforce; Pieter Jelle Visser; Rik Ossenkoppele Journal: Ann Neurol Date: 2018-11 Impact factor: 10.422
Authors: S M Schaafsma; B J Riedstra; K A Pfannkuche; A Bouma; T G G Groothuis Journal: Philos Trans R Soc Lond B Biol Sci Date: 2009-04-12 Impact factor: 6.237
Authors: Dorothea L Floris; Lindsay R Chura; Rosemary J Holt; John Suckling; Edward T Bullmore; Simon Baron-Cohen; Michael D Spencer Journal: J Autism Dev Disord Date: 2013-08