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Differential psychology/psychometrics

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Read more about the article Skin color and intelligence in Latin America

Skin color and intelligence in Latin America

  • Post author:Emil O. W. Kirkegaard
  • Post published:11. May 2026
  • Post category:intelligence / IQ / cognitive ability/Sociology

Skin color (lightness or brightness) has been used as a proxy for genetic ancestry for over 100 years. It works alright in many cases. Take this study (Parra et al…

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Read more about the article Race, intelligence, and inequality in Brazil

Race, intelligence, and inequality in Brazil

  • Post author:Emil O. W. Kirkegaard
  • Post published:7. May 2026
  • Post category:intelligence / IQ / cognitive ability/Sociology

Many years ago I discovered that Brazil publishes the subject level data for many scale testing efforts. These also come with rich surveys concerning the children's homes. The main tests…

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Read more about the article Genetic evidence of Ashkenazi intelligence

Genetic evidence of Ashkenazi intelligence

  • Post author:Emil O. W. Kirkegaard
  • Post published:29. April 2026
  • Post category:Genomics/intelligence / IQ / cognitive ability

There are long standing questions about the source of Jewish achievement. Most of this achievement relates to the Ashkenazi subgroup, less so the other Jews. This tells us that the…

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Read more about the article Explaining economic growth since 2000

Explaining economic growth since 2000

  • Post author:Emil O. W. Kirkegaard
  • Post published:28. April 2026
  • Post category:Economics/intelligence / IQ / cognitive ability

Some days ago I posted some cumulative growth charts for OECD countries, like this one: These results are somewhat affected by the usual GDP issues relating to tax haven (Ireland…

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Read more about the article Leftism, mental health, and visual presentation confirmed

Leftism, mental health, and visual presentation confirmed

  • Post author:Emil O. W. Kirkegaard
  • Post published:20. April 2026
  • Post category:Differential psychology/psychometrics

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…

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Read more about the article Migration and feelings of safety in Denmark

Migration and feelings of safety in Denmark

  • Post author:Emil O. W. Kirkegaard
  • Post published:18. April 2026
  • Post category:Differential psychology/psychometrics/Immigration

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…

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Read more about the article American Jewish gentile differences

American Jewish gentile differences

  • Post author:Emil O. W. Kirkegaard
  • Post published:9. April 2026
  • Post category:intelligence / IQ / cognitive ability/Stereotypes

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…

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Assessment of the Confidence Calibration Test + new test

  • Post author:Emil O. W. Kirkegaard
  • Post published:4. April 2026
  • Post category:intelligence / IQ / cognitive ability

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…

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Read more about the article Which countries are best at esports? 2026 update

Which countries are best at esports? 2026 update

  • Post author:Emil O. W. Kirkegaard
  • Post published:2. April 2026
  • Post category:intelligence / IQ / cognitive ability/Media studies

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…

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Read more about the article Meta-Analysis of American Race Differences in Intelligence

Meta-Analysis of American Race Differences in Intelligence

  • Post author:Emil O. W. Kirkegaard
  • Post published:30. March 2026
  • Post category:intelligence / IQ / cognitive ability

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.…

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