Even if you have a brain predisposed to liberalism, you might end up with some conservative friends or find inspiring conservative role models who could be very influential on you, and that could send you down a different track in life.

If you have high IQ, you're really good at finding post-hoc arguments to support your feelings of truthiness.

If you have a personality predisposed to liberalism, you might gravitate more to the artsy crowd or the anti-establishment crowd. And then those peers will affect you, and they will give you values, and you will copy them.

Jonathan Haidt Quotes