From my experience, many psychologists choose the field because they have mental issues. Liberalism, by being rooted in emotion and the desire to eschew logic or rational thought, tends to appeal to the mentally imbalanced. So, is it any surprise that most psychologists are liberal?
Everybody has “mental issues” as you put it. Some deal with them better than others. A good psychologist can help, regardless of political persuasion. A bad psychologist is like a bad plumber - get ‘em out of there before they cause too much damage.
Most psychologists are liberal because of academic orthodoxy,and its rigorous requirements. Psychologists in the public sector (VAs, academia) are far more liberal than private sector psychologists who deal with reality on a day-to-day basis.
-25 years a conservative libertarian psychologist who mostly keeps his mouth shut in professional circles.
Not knowing any shrinks or psychologists, I can neither agree nor disagree with the mental issues argument. However, I think that particular field draws a lot of libs because it represents a study in which many of it's participants believe in the blank slate theory. The bs theory for short. They love the idea that humans are blank canvases unto which any idea can be flung rather that minds that are hardwired in many ways.
These are the people who told us that all behavior is learned and that there are no natural mental talents, just people who had better life situations. I remember reading a book about Hitler called "The Psychopathic God" wherein every evil thing Hitler did was attributed to him reacting to a scene from his early life. Total gibberish.
Libs love the bs theory, because it helps rationalize the fact that humans are not born equal and is unfair. Therefore, under liberalism, and with the help of liberal psychologists and their ilk, they can make the world fair and equal.