I did quite a bit of research on this in the mid 00’s when a number of left leaning surveys were published that I was pretty sure were wrong. They were.
(Especially about mental illness, which appears to be a near monopoly on the left because of the dominance of women on the left. Why? Because males demonstrate anti social behavior by criminality and females demonstrate antisocial behavior by psychosis. Hence why a third of american women are on anti-depressants.)
Here is the summary:
a) Republicans are smarter than democrats.
b) Liberals are smarter than conservatives.
c) And libertarians are smartest of all.
d) People vote by moral intuition because they have no other choice under representative first-past-the-post, two party, government. (See “Myth of the Rational Voter”.)
e) Men bias to organize by packs (precision at the cost of consensus), and women bias to organize as herd (consensus at the cost of precision). This means men are less likely to pursue consensus, and instead specialize. Hence the relative heterogeneity of the right compared to the relative homogeneity of the left. Ergo democracies always move left until failure while anglo civilization using hoses for the classes merely had civil wars to reorganize the law to include newly productive classes.
f) People vote heavily by race and religion, with single white women the only group ‘defecting’. In some sense, single women determine most presidential outcomes for this reason. Without women voters we would never have had a leftist president. (See Pew.)
Why? There are very (painfully) obvious reasons:
1 – Advocates use college degrees as a proxy for intelligence without mediating for the IQ distribution of degrees. In other words, a Phd in Education is rated more highly than bachelors degree in engineering or computer science, yet graduates with those degrees possess the inverse IQ relationship.
2 – Women at the lower end of the distribution disproportionately obtain (nonsense) degrees while men simply enter the work force without them.
3 – There are very few liberals, and very many conservatives. There are very few libertarians and very many democrats. In other words, when you compare democrats and republicans that’s categorically the same as comparing libertarians and leftists. The difference is that liberals will have soft degrees and libertarians will have hard (STEM) degrees. But if you mix categories (liberals and conservatives) then you are comparing vastly different distributions by very different criteria.
<- Liberal -- Democrat - independent - Republican -- Libertarian -> <- Female Reproductive Strategy <---> Male Reproductive Strategy ->