Bridging Sex and Gender in Neuroscience by Shedding a priori Assumptions of Causality

Notable for the current discussion, there is compelling evidence for at least limited theory of mind (i.e., the ability to recognize mental states in others such as their goals, intentions, perceptions, knowledge, and/or beliefs) in diverse non-human animals. Whereas it is important to acknowledge doubt concerning the extent to which the adaptive performance of other animals or even human infants reflects true understanding of the mental states of others rather than resulting from more simple behavioral rules (see Penn and Povinelli, 2007), we believe it is fair to say diverse species have remarkably sophisticated social behavior, enabling behavioral responses that adapt to mental states of conspecifics. [...]in bluehead wrasse (Thalassoma bifasciatum), adult females can undergo complete sex change based on social cues, becoming sperm-producing males if the existing dominant male is removed from their habitat (Warner and Swearer, 1991). Discussion about the intersections between genes and environment in the evolution of human sex and gender differences is ongoing (e.g., Smuts, 1995; Eagly and Wood, 2013; Liesen, 2013; Neuberg and Sng, 2013; Barker, 2015) and it has been argued that the social environment and/or culture are not entirely distinct from genetic and epigenetic mechanisms (see for example Jablonka and Lamb, 2014; Fine et al., 2017).