https://www.sciencedirect.com/science/article/abs/pii/S0160289624000254?via%3Dihub

The original study:

https://www.sciencedirect.com/science/article/abs/pii/S0160289624000254?via%3Dihub

Main points:

Within-families, intelligence predict left-wing beliefs.


DNA-based predictors of IQ also predict political beliefs within families.


Our results imply that being genetically predisposed to be smarter causes left-wing beliefs.

Abstract:

Intelligence is correlated with a range of left-wing and liberal political beliefs. This may suggest intelligence directly alters our political views. Alternatively, the association may be confounded or mediated by socioeconomic and environmental factors. We studied the effect of intelligence within a sample of over 300 biological and adoptive families, using both measured IQ and polygenic scores for cognitive performance and educational attainment. We found both IQ and polygenic scores significantly predicted all six of our political scales. Polygenic scores predicted social liberalism and lower authoritarianism, within-families. Intelligence was able to significantly predict social liberalism and lower authoritarianism, within families, even after controlling for socioeconomic variables. Our findings may provide the strongest causal inference to date of intelligence directly affecting political beliefs.

Hah, I always knew my political beliefs were proof of my genetic superiority.

~~But seriously, this isn't necessarily saying what some people assume it's saying. I don't have much confidence in "controlling for socioeconomic variables" so I think membership in an intellectual class and therefore adherence to the beliefs common among that class may be the explanation for this phenomenon (rather than "smart people can figure out what the right answer to politics is").~~

Edit: I've thought about it and I think it's unfair for me to cast doubt on the study's controls without listing specific objections. I withdraw my comment, at least until I have time to read the full study carefully.

Any study that related intelligence to opinion is inherently inflammatory. It invites dismissiveness instead of engagement, excuses rude behavior, and presumes that certain opinions are so dumb the holder is incapable of growth. I get the satisfaction in giving me a hard time, but if we ever want to be any kind of enlightened we’re going to have to disagree without insulting each other.

Consider that scholastic opportunity is much much higher in urban environments and that city folk tend to be more liberal. Consider that intelligence is difficult to define or measure - for instance, urbanites can’t tell the difference between a yellow jacket and a dirty dobber. That qualifies as stupid on some life tests. These are just two logical example of how confounding variables might lead to inaccurate and sloppy findings.

For the record, modern Rs aren’t conservative. They have no integrity and how can you stand for anything if you lack that? They are opportunistic amoral power hungry manipulators. However, you can’t see their excessive narcissism and conclude that Ds are good, that’s just a weird inverted ad hominem.

Winston Churchill said anyone under 30 who’s not a liberal has no heart. Anyone over thirty who isn’t conservative has no brain.