Two intersecting aspects of psychology may be particularly relevant to issues around sex and gender. One is self perception (who do I think I am?) and the other is group dynamics (how do the people around me / those with whom I associate) defend my / our identities?
Every person has an identity and character shaped by both genetics and context. These factors become even more complex when considering group psychology, which has dynamics even beyond those influencing individual behaviour.
This becomes relevant to many perspectives and much decision-making. People in groups often make decisions or choices which are more ‘extreme’ than the ones they would likely have made as individuals. This phenomenon, group polarisation, can have significant impact on the positioning of those seeking to clarify or resolve issues of common concern. This tendency may be further exacerbated by reference to social media such as Twitter or Facebook, and can also lead to attitude polarisation, where groups become increasingly distant from each other in the course of disagreements.
It might be thought that such polarisation has occurred in respect of some aspects of the current debates about gender and sex.
Another important finding in social psychology is that some groups of people, who have experiences of trauma which they then share with each other, may become isolated and exclusionary of others. This tendency is explored by amongst others the psychiatrist Bessel van der Kolk.
Eric W, Dolan, Young women’s psychological distress increases when they change their identity away from the heterosexual norm
Stats for Gender (data website with much valuable information)