So we did another study of leftism, mental health and visual presentation: Hu, M.,& Kirkegaard, E. O. W.(2026). Left-wing ideology, mental health and body modifications. Journal of Open Inquiry in…
A politician from the Social Democrats called Frederik Vad (center-left government party) posted results of a survey about how safe citizens report feeling in various areas of the country. There…
Jews are an extraordinarily successful ethnic group in almost everything they choose to engage in, from physics to politics with the curious exception of US presidencies. Seb Jensen compiled a…
Yesterday, I posted a new cognitive test on taketest.xyz, the Confidence Calibration Test. If you want to take the test without biased results, take it now before reading further. You…
Given the ease of obtaining scraped datasets with Claude Code, I thought we could update my 2019 study of mental sports with the newest data and better methods. The primary…
So our new meta-analysis of the American race gaps in IQ is published! Kirkegaard, E. & Jensen, S. (2025). Meta-Analysis of American Race Differences in Intelligence. Mankind Quarterly, 66(2), 290-300.…
Some time ago, we published studies showing that the negative correlation between intelligence and fertility varies by other factors. Specifically, we found that it varies by religiousness and conservatism, in…
Years ago, a very flashy finding by Kahan and colleagues (2017) got popular (1200+ citations). It goes like this, you give people some matrices of fake study data like these:…
Using Claude code I am realizing some projects that were always waiting for a sudden burst of manic energy. These projects now only take some hours of chatting and revising…
In my recent post about differences on the tails, a good comment was posted by Kristine: Is there any correlation between IQ gap and divorce, I wonder... The generation observation…