'No less a psychologist - in the sense that he's not known for the social dimensions of his thought - than Freud thought that the ego was formed in part by models appropriate to "family, class, and nation." The stresses experienced by individual families, not to mention norms, are heavily shaped by the society people live in, and their particular niche in it. All the ideas around guns and masculinity - social. Ditto the alienation experienced by various nerds and misfits.'
But Freud - who after all founded psychoanalysis as a distinctive discipline - understood the difference between his psychology and sociology. It was through analysis of the individual subject that he sought to understand the processes at work. In fact it was a weakness of Freud's that he tended in his later essays to imagine that you could explain society in terms drawn from his psychoanalysis (Civilisation and its Discontents). That was to make the mirror-image mistake of the one that you are making, namely to subsume the one discipline to the other.
Your Cod-sociology 'all the ideas around guns and masculinity - social. Ditto the alienation experienced by various nerds and misfits' tells us sweet Fanny Adams about why Adam Lanza did what he did. Otherwise many people would be doing it, whereas by any statistical measure this is a very exceptional event.
You express doubt about the biological bases of many psychological processes. But psychologists don't. A great deal of psychology is about things that I think you would think are boring, or off the point, like reflexes, memory, or the synaptic bases of 'deja vu'.
Current thinking on both autism, schizophrenia and bipolar disorder is that all have a strong genetic component. The Laingian view that insanity was a proper reaction to an insane sociey has not proved as strong a foundation for clinical work as was at first hoped - a point that Laing himself conceded, and was explained best by (Victor Serge's translator) Peter Sedgwick in his book Psychopolitics.
Your charge that I am following a 'party line' which accusation, apart from being the hallmark of petit bourgeois individualism, seems to me ironic for another reason. Your own attempt to subsume psychology into social science echoes strongly of those 1930s Communists who thought that Marxism would become a general science that would explain all questions, from economics to the solar system, psychology and ancient history. More recently Marxist thinking has tended in the other direction, insisting on the specificity of Marxism to the analysis of capitalist accumulation, and abandoning the more fantastic ambitions for a Marxist linguistics, or a Marxist theory of art, or a Marxist physics, or a Marxist analysis of ancient societies. Marxist psychology, I think, ought to go into the same rubbish bin.