Psychology: a Giant with Feet of Clay.

The aim of the current study has been to highlight the theoretical precariousness of Psychology. The theoretical precariousness has been evidenced through a review of psychological "core-constructs" whose definitions were thoroughly searched in 11 popular introductory textbooks of psychology edited between 2012 and 2019 and in an APA dictionary of Psychology (VandeBos 2015). This analysis has shown unsatisfactory or discordant definitions of psychological "core-constructs". A further epistemological comparison between psychology and three "harder" sciences (i.e., physics, chemistry and biology) seemed to support the "soft" nature of psychology: a minor consensus in its "core" and a minor capacity to accumulate knowledge when compared to the former "harder" sciences (Fanelli in PLoS One, 5, e10068, 2010; Fanelli and Glänzel in PLoS One, 8, e66938, 2013). This comparison also seemed to support the "pre-paradigmatic" condition of psychology, in which conflicts between rival schools of thought hamper the development of a real unified paradigm (Kuhn 1970). To enter a paradigmatic stage, we propose here evolutionary psychology as the most compelling approach, thanks to its empirical support and theoretical consistency. However, since the skepticism about "grand unifying theories" is well disposed (Badcock in Review of General Psychology, 16, 10-23, 2012), we suggest that evolutionary psychology must be intended as a pluralistic approach rather than a monolithic one, and that its main strength is its capacity to resolve the nature-nurture dialectics.