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"Consciousness is not the same thing as intelligence. Consciousness is about being and feeling; intelligence — very broadly — is all about doing, or performing functions. Just because something is intelligent does not mean that it is conscious."

There's new progress on understanding the genetics of cognitive abilities! @dielondono and his coauthors examined the molecular genetics of cognitive abilities and how they relate to personality and mental health conditions. Results from this important GWAS include: ➡️Overlap for genetic loci associated with fluid intelligence, crystallized intelligence, and reaction time. but there are also DNA variants that are only associated with one ability. We can't just assume that a gene that impacts one cognitive ability will impact others. ➡️Among loci with known functions, most are expressed in the brain. But there are some surprises, including DNA variants association between crystallized intelligence possibly being expressed in the ovaries (2nd image). ➡️Different genetic correlations with mental health conditions (3rd and 4th images). For example, there is a positive genetic correlation between crystallized intelligence and autism spectrum disorder, but a negative genetic correlation between crystallized intelligence and ADHD. This may explain why some common DNA variants associated with mental health conditions remain in the human gene pool: maybe some of these variants are sometimes beneficial. ➡️Personality traits also showed differing genetic correlations with the cognitive traits. The strongest genetic correlation was between crystallized intelligence and openness to experience (r = .465; 4th image). These correlations give important clues into the development of these cognitive abilities and how they build phenotypes like knowledge, reasoning ability, etc. ➡️New genetic loci associated with crystalliezed intelligence. This study shows convincingly the value of examining the genetics of broad cognitive abilities--instead of just focusing on general intelligence. It also provides insight into the genetics of intelligence and how it relates to other abilities. Read the full study (with no paywall) at doi.org/10.1038/s41467-026-7…

Good news for efforts to raise educational achievement in developing countries! A new article in @ICAJournal uses cross-national data to find evidence that improved nutrition can increase academic achievement scores. The authors compared average height differences between males and females in over 100 countries, which is an indirect measure of nutritional quality before adulthood: because males are more vulnerable to stunting, countries with a larger male-female height difference have better nutrition. These differences were then compared to average academic achievement scores for the different countries to find if there was a relationship. The results indicate that countries with a larger male-female height difference do indeed have higher academic achievement scores. However, this relationship levels off after an 8% height difference (grey scatterplots in 2nd image), but it's still large: a 1% difference in male-female heights is associated with a d = .2 to .3 increase in academice achievement. This provides circumstantial evidence that improving nutrition in developing nations will provide educational benefits down the road. However, the leveling off also shows that there are limits to the cognitive gains that can be expected from improved nutrition. The results were replicated with datasets at the region/state level within 5 of 7 countries (see 3rd image). But, for unknown reasons, it did not replicate within Russia or India. Additionally, this study does not state how much of the increase in test scores is due to actual nutrition, or to other influences that might also emerge at the same time as nutrition improvements, such as increased economic development or a better education system. The study is very informative regarding about the origin of cross-national differences in academic achievement. Read the full article (no paywall) at doi.org/10.65550/001c.166704

The heritability of general is well established at ~50%. But what about more specific abilities? A meta-analysis of nearly 750,000 twins reveals fascinating results: ➡️Specific cognitive abilities average 56% heritability, which is about the same as for general intelligence. But there was substantial variability, ranging from 39% for auditory processing to 64% for quantitative knowledge (see 2nd image). ➡️Unlike intelligence, specific cognitive abilities don't have an apparent developmental trajectory in heritability. Instead of increasing with age, specific cognitive abilities seem to maintain the same level of heritability at different age spans. ➡️The heritability of specific cognitive abilities seems to be independent of the genetic influence of general intelligence. ➡️Specific abilities within the same category sometimes differ in their heritability. Reaction time heritability was 42%, but processing speed heritability was 64%, even though both are classified as "mental speed." ➡️Substantial heritability does not rule out important environmental effects. Shared environmental influence was as high as 26% for knowledge scores and 20% for fluid intelligence. This meta-analysis isn't just useful as a research summary. It also reveals the potential for future research. The authors point out that some abilities have little or no research on their heritability, others don't have enough information at some age ranges to draw conclusions about developmental trajectories. This is meta-analysis is definitely not the last word on this topic. Read the full study (with no paywall) here: doi.org/10.1016/j.intell.202…

Raise a glass to the newest study in @ICAJournal from Maximilian Krolo and @timothycbates, who find that smarter people know more about wine. 🍷 In a sample of 525 respondents, IQ and wine knowledge were positively correlated (r = .31), and this relationship did NOT diminish after controlling for exposure to the wine industry or drinking habits. If you're not a sommelier, this correlation doesn't matter much in real life. But the study has a lot of theoretical importance. Wine knowledge is complex, sophisticated, not taught in schools, and has little practical application for most people. This undermines the theory that smarter people know more facts because they have economic incentives to learn more or because they attend school longer. The people who knew the most about wine were those who had both (1) high IQ and (2) exposure to the wine industry. This likely means that exposure to a knowledge domain occurs that smarter people benefit more from that environment than less intelligent people. Cheers to the authors! 🥂 Read the full study (with no paywall) at doi.org/10.65550/001c.165719

It's a classic "chicken and the egg" problem: does high intelligence cause better educational outcomes, or does succeeding in school cause improved performance on intelligence tests? 🐔🥚🧠🎓 A study in Germany investigated this question with six longitudinal samples and found that the relationship between fluid intelligence and academic achievement is reciprocal. In other words, there is a feedback loop in place: high fluid intelligence ➡️ higher academic achievement ➡️ higher fluid intelligence test performance ➡️ higher academic performance ➡️ etc. As the authors stated, ""Not only did fluid intelligence foster the development of achievement; achievement also fostered the development of fluid intelligence. . . . any measure of prior achievement is already a function of that person's fluid intelligence" (p. 6). This feedback loop applies to both math and reading achievement and for both males and females. Read the full article at doi.org/10.1016/j.intell.202…

Our Chief Scientist, @Russwarne, is the author of a new article in @EducationNext. In it, he explains: ➡️Shortcomings of the "treasure hunt" model of selecting kids for programs ➡️Why "giftedness" doesn't really exist ➡️What "gifted" education can learn from clinical psychology about labeling ➡️Why there are no "gifted" adults Read it here: educationnext.org/gifted-is-…

RT @Russwarne: I have a new article published in @EducationNext! Learn why the "gifted" label causes more problems than it solves--and why…

A banger article in @ICAJournal reports the impact of intelligence and specific cognitive abilities on education level, socioeconomic status, and occupational prestige. Using data from the NLSY79 and NLSY97 samples, the authors replicated previous work showing that there is a hierarchy of jobs in which those with higher average IQs have greater prestige and pay. What's new in this article is that that--after controlling for general intelligence--the authors did the same analysis for specific abilities: tech (mechanical knowledge), math-verbal abilities, and processing speed. The results are fascinating: ➡️Jobs with workers who have higher average math-verbal scores tended to also be the same jobs with higher IQ (2nd image). ➡️Tech/mechanical knowledge tends to predict lower prestige, pay, and IQ. But there are exceptions: engineers tend to have high IQ, high tech levels, greater pay, and high prestige. ➡️Cognitive abilities and job interests are correlated. IQ is negatively correlated with realistic interests and most positively correlated with investigative interests (3rd image). ➡️The importance of different abilities fluctuates in the early 20s before stabilitizing. In early adulthood, high tech ability is associated with higher income, but that reverses after a few years (4th image). Apparently, a young person can enter a job with high tech ablity needs relatively quickly (e.g., electrician, factory work). But after a person with higher IQ or verbal-math ability gets some college training, they can ener a higher paying job in their mid 20s. This is a strong article that builds on knowledge, replicates old findings, and pushes the field forward with information that both theoretically and practically useful. Read the full article here: doi.org/10.65550/001c.162975

The first author of this article was a guest on our podcast last year. Here she is replicating her work showing the massive range of academic preparedness within classrooms. youtu.be/SenIUvVpLTQ?is=-0Fu…