Transracial adoption study: Bruce et al (2009)

Introduction This is a post in the on-going series of comments on studies of international/transracial adoption. A global genetic/hereditarian model of cognitive differences and their socioeconomic effects implies that adoptees from different populations/countries/regions should show the usual group differences in the above mentioned traits and outcomes, all else equal. All else is of course not…

Continue Reading

The S factor in the British Isles: A reanalysis of Lynn (1979)

Read the study PDF. Emil O. W. Kirkegaard, Ulster Institute for Social Research. Email: emil@emilkirkegaard.dk Abstract I reanalyze data reported by Richard Lynn in a 1979 paper concerning IQ and socioeconomic variables in 12 regions of the United Kingdom as well as Ireland. I find a substantial S factor across regions (66% of variance with MinRes…

Continue Reading

Transracial adoption study: Stams et al, 2000

This is another relatively small international adoption study. 159 children were adopted in homes in the Netherlands from Sri Lanka, Korea and Colombia. Participants are described as: The present study examines the development and adjustment of 159 adopted children at age 7 years. The largest group, 129 adopted children, was selected from 2 studies, starting…

Continue Reading

Spearman’s hypothesis on item-level data from Raven’s Standard Progressive Matrices: A replication and extension

Emil O. W. Kirkegaard1 Abstract Item-level data from Raven’s Standard Progressive Matrices was compiled for 12 diverse groups from previously published studies. Jensen’s method (method of correlated vectors) was used on every possible pair of groups with available data (45 comparisons). The mean Jensen coefficient was about .50. Very few were negative. Spearman’s hypothesis is…

Continue Reading

International differences in intelligence can be confusing: A commentary on Harrison et al (2015)

Abstract In this commentary I explain how mean differences between normal distributions give rise to different percentages of the populations being above or below a given threshold, depending on where the threshold is. Introduction “Research uncovers flawed IQ scoring system” is the headline on phys.org, which often posts news about research from other fields. It…

Continue Reading

How to integrate Winnower, blog posts and ResearchGate?

Abstract I argue that traditional scientific publication is extremely costly and that scientific publication must move towards more rapid publication practices. I discuss how this might be accomplished by integrating blogposts, The Winnower and ResearchGate. Introduction There are a number of important dimensions that scientists consider when they choose how and where to publish their…

Continue Reading

Opinions about nuclear energy and global warming, and wordsum intelligence

Abstract Using data from the ANES 2012 survey, I investigate the relationship between wordsum IQ estimates (unweighted sums, factor analytic and item-response theory scores) and opinions about nuclear energy and global warming and related beliefs. Proponents of nuclear energy were found to have somewhat higher IQs (103) than those who think we should have fewer…

Continue Reading

Review: The Righteous Mind: Why Good People are Divided by Politics and Religion (Jonathan Haidt)

https://www.goodreads.com/book/show/11324722-the-righteous-mind I had heard good things about this book, sort of. It has been cited a lot. Enough that I would be wiling to read it, given that the author has written at least one interesting paper (Political Diversity Will Improve Social Psychological Science). Generally, it is written in popsci style, very few statistics making…

Continue Reading