I wrote a whole book on it. The gist is, they never exercise or develop the amygdala, which is what handles stress and processes it into productive action. Since the structure is undeveloped, it cannot handle stress productively, and panics when it encounters it, and as a defensive mechanism the leftist brain will activate denial to stop the signals hitting the amygdala.
MRIs will show measurably smaller amygdalae in leftists compared to conservatives. It is actually a behavioral adaptation though - a functional adaptive mechanism meant for times when there is less stress and danger, like gluts of food. Since the amygdala is shown to drive the K-selected wolf-like traits of combativeness and competitiveness, as well as loyalty, when it is weaker the behavior turns more r-selected, like a rabbit, increasing sex drive, and it makes them more rabbit-like, which is actually good for their reproduction in a glut.
Search MRI amygdala and ideology for more.
I actually dropped all of that and focused on the real problem in America, which is a massive Secret Police agency they have hidden, which operates just like the Stasi. That showed up to harass me due to my research, and since then I think liberals are about .01% of the problems America faces, and 99.9% is the American Stasi.
Good info. Your home page is interesting also.