One interesting take on this is that certain attitudes such as "authoritarian" or "egalitarian" both have value in the sense of the "selfish-gene" evolutionary theory.

So for example, imagine a primitive tribe of humans facing a drought. If they spend too much time discussing options democratically, if they don't all agree, or if they waste time by changing their mind half-way to a source of water, they'll all die. But if they follow an authoritative leader -- even if makes bad arguments or none at all -- they might all make it to the mountain spring in the distance and survive.

The gist of this is that in times of hardship, authoritarian, conservative, or "right-wing" styles of though/argument/politics/whatever can win the day. But in times of relatively low stress, more democractic/left-wing/progressive attitudes can help the tribe discover even more resources than they would have if they always followed the same instructions to go to the same sources. Innovation and exploration can turn the merely adequate into a bountiful plenty, resulting in more healthy babies, etc...

So these attitudes and personality traits are important to have present in the gene pool to make the species as a whole robust against a wide range of challenges and threats.