Fertility and Family Labor Supply. Katrine Jakobsen and colleagues examine whether the effect of earnings on fertility differs between men and women. Analysing Danish register data, they find that higher earnings reduce fertility among women but raise fertility among men. This suggests that the substitution effect dominates for women, while the income effect dominates for men.

Performative virtue-signaling has become a threat to higher ed. Forest Romm and Kevin Waldman report results from a survey of students at two major US universities. They asked, “Have you ever pretended to hold more progressive views than you truly endorse to succeed socially or academically?” and found that 88% said yes. Four out of five had misrepresented their views to align with professors, and more than three quarters had self-censored.

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Converging evidence of positive selection at height-associated loci in Europe. Valentin Hivert and colleagues re-examine evidence of positive selection for height in Europe. Combining within-family GWAS designs with allele frequency estimates from 13 European populations, they detect signals of positive selection both within and between populations. The between-population signal is driven by the difference between the Dutch and other populations.

How Test Optional Policies in College Admissions Disproportionately Harm High Achieving Applicants from Disadvantaged Backgrounds. Bruce Sacerdote and colleagues examine to what extent “test optional” policies in admissions harm high-achieving students from disadvantaged backgrounds. They find that test scores are the best predictors of success in college, and under “test optional” policies, applications from disadvantaged backgrounds are much less likely to submit scores.

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Alcohol, Violence, and Injury-Induced Mortality: Evidence from a Modern-Day Prohibition. Kai Barron and colleagues examine the impact of South Africa’s five-week alcohol ban in July 2020. Comparing the year of the ban to previous years, they find that it led to a substantial 14% reduction in the total number of unnatural deaths. They also find that it led to a temporary reduction in violent crime, particularly rape.

A gender gap in gender gaps: social norms and housework reporting. Martin Acht and Mara Rebaudo examine the impact of the interviewer’s gender on reporting of time spent on housework in social surveys. Analysing data from Germany, they find that women report significantly more time spent on housework when interviewed by a woman. By contrast, interviewer’s gender does not affect men’s reporting. These results may be explained by intrasexual competition among women.

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How foreign wars can consolidate authoritarian power: Evidence from Russia’s invasion of Ukraine. Mikael Elinder and colleagues analyse public opinion data from Russia during the War in Ukraine. Analysing data from both Russian and American pollsters, they find that Russians became more supportive of Putin, with an effect seen in almost every demographic group. Russians also became more optimistic about the future and even slightly happier.

The role of pre- and post-birth factors in the transmission of political engagement. Aaron Weinschenk and Christopher Dawes examine the transmission of political engagement using data from a major adoption study. They find that adopted children are more similar in terms of engagement to their biological parents than to their adoptive parents — though due to low power, not all the differences are statistically significant.

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Earliest evidence of making fire. Rob Davis and colleagues present the earliest evidence of fire making by early Neanderthals or other Homo species from a site in southeast England. The evidence dates to 400,000 years ago, and includes burnt surfaces, fire-cracked handaxes and fragments of iron pyrite (which is known to have been used in later periods to make sparks). Previous examples of early fire use were consistent with human exploitation of natural fires.

On the relationship between indirect measures of Black vs. White racial attitudes and discriminatory outcomes. Jordan Axt and colleagues examine whether implicit (i.e., subconscious) racial attitudes influence discriminatory behaviour by white Americans via an adversarial collaboration. They find that such attitudes can predict discriminatory behaviour beyond the effect of explicit (i.e., self-reported) attitudes, though their effect is far smaller, accounting for only 2.5% of the variance.

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Science can address meaning and purpose. Coel Hellier responds to Bo Winegard’s recent article on science and meaning. He argues that science can discover meaning and that notions of hope, love and mortality are within the purview of science. Hellier maintains that to ask “what is the meaning of life?” is a category error because meaning and purpose can only be understood from the perspective of particular sentient organisms.

Physical attractiveness predicts endorsement of specific evolutionary psychology principles. Andrew Ward and colleagues examine whether physical attractiveness is associated with endorsement of principles from evolutionary psychology. Across two studies, one observational and one experimental, they find that it is. Observer-rated physical attractiveness was a stronger predictor of endorsement of such principles than gender or political orientation.

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The potential existential threat of large language models to online survey research. Sean Westwood examines the viability of online survey research (a very important source of findings) in the era of LLMs. He shows that LLMs can be programmed to answer online surveys in ways that are indistinguishable from humans, with “synthetic respondents” passing standard bot checks 99% of the time. Such respondents could be used by foreign actors to manipulate public opinion.

The metabolic costs of cognition. Sharna Jamadar and colleagues review the literature on the metabolic costs of cognition in humans. They note that while the brain uses the most energy of any organ in the body, it is remarkably energy efficient. Thanks to various optimisation mechanisms, goal-directed cognition uses only 5% more energy than resting neural activity. Cognitive decline in old age is associated with disruption of neural energy homeostasis.

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A biobank-scale test of marginal epistasis reveals genome-wide signals of polygenic interaction effects. Boyang Fu and colleagues examine the contribution of genetic interactions (epistasis) to variation in human complex traits. Analysing data on 300,000 British people, they detect 16 significant genetic interactions across 12 traits. These account for tiny fractions of the overall variance, though the effect sizes are larger than the GWAS effect sizes for the same variants.

What role for “generational wealth” in explaining racial wealth disparities? John Sabelhaus and Jeffrey Thompson re-examine the literature on intergenerational wealth transfers as a source of racial wealth disparities. Analysing more recent data on a wider range of assets, their findings are consistent with those of previous studies: intergenerational transfers can only account for a small part of the racial disparities.

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Readers Prefer Outputs of AI Trained on Copyrighted Books over Expert Human Writers. Tuhin Chakrabarty and colleagues examine whether humans prefer AI-generated versus human-written texts emulating the work of award-winning authors. In blind judgements, humans strongly preferred the texts generated by AIs trained on the authors’ works. They rated the AI-generated texts higher on both overall quality and stylistic fidelity.

The Increasing Frequency of Terms Denoting Political Extremism in U.S. and U.K. News Media. David Rozado and Eric Kaufmann examine the frequency of terms denoting political extremism in more than 30 million news articles from the US and UK for the period 1970–2019. They document a large rise in the frequency of terms referring to far-right extremism, beginning around 2010. This rise is particularly pronounced in left-leaning news outlets.

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Genetic associations with educational fields. Rosa Cheesman and colleagues carry out a genome-wide association study of educational field choice using a large sample from Finland, Norway and the Netherlands. They identify 17 genetic loci independently associated with choice of field — after controlling for years of schooling and other background factors. Analysing genetic correlations across field choices, they uncover two dimensions: technical versus social and practical versus abstract.

Testing the Late Pleistocene Arctic Origins of East Asian Psychology using Ancient and Modern DNA. Davide Piffer tests the theory that arctic climates in the late Pleistocene shaped East Asian psychology. He finds that populations living at high latitudes have lower average polygenic scores for extraversion and neuroticism, and higher average scores for agreeableness. And he finds that these associations become weaker when controlling for ancient Northeast Asian ancestry.

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Physical activity is directly associated with total energy expenditure without evidence of constraint or compensation. Kristen Howard and colleagues test the theory that exercise does not substantially raise total energy expenditure due to compensatory changes in response to exercise (e.g., less fidgeting, lower thyroid function). They find no evidence for this theory: exercise is not associated with any biomarkers of compensatory change.

Individual differences in bitter taste preferences are associated with antisocial personality traits. Christina Sagioglou and Tobias Greitemeyer examine the relationship between taste preferences and personality in two American samples. In both cases, they find that individuals express a preference for bitter foods score higher on measures of antisocial personality, especially sadism and psychopathy. Other taste preferences were much less predictive.

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The kernel of truth in gender stereotypes: Consider the avocado, not the apple. Alice Eagly and Judith Hall meta-analyse studies of stereotype accuracy concerning sex differences. They find high levels of accuracy. Across 673 estimates, 85% were in the correct direction (meaning that participants correctly identified that men or women scored higher on some trait). The authors report an average consensual stereotype accuracy correlation of r = .77.

From Worriers to Warriors: The Cultural Rise of Women. Cory Clark reviews the evidence concerning the impact of rising female representation in academia and other institutions. She noted that the rise has directly contributed to cancel culture and to policies like DEI, trigger warnings and safe spaces. She argues that these phenomena reflect female psychology — specifically, aversion to harm, protecting the vulnerable and resolving conflict through social exclusion.

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The dark side of the rainbow: Homosexuals and bisexuals have higher Dark Triad traits than heterosexuals. Peter Jonason and Severi Luoto examine whether Dark Triad traits vary by sexual orientation. In a cross-national sample, they find that bisexual women score significantly higher than heterosexual women on all three Dark Triad traits. This finding contradicts the pro-sociality hypothesis of same-sex attraction.

News coverage and mass shootings in the US. Michael Jetter and Jay Walker examine whether media coverage of mass shootings leads to “copycat” shootings in subsequent days. By comparing shootings that occurred around the same time as natural disasters (and were therefore not covered as extensively in the media) to those that weren’t, they find that media coverage has a sizeable “copycat” effect.

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Within-family heritability estimates for behavioural and disease phenotypes from 500,000 sibling pairs of diverse ancestries. Loic Yengo and colleagues estimate heritability for a number of traits using a large sample of sibling pairs drawn from 23andMe. Exploiting purely within-family variation (and thereby controlling for factors shared by siblings), they obtain an estimate of .70 for height and .49 for BMI. The authors were unable to analyse cognitive ability due to ethics restrictions.

Does Wealth Inhibit Criminal Behavior? Evidence From Swedish Lottery Winners and Their Children. David Cesarini and colleagues examine whether having more money stops people from committing crime in Sweden. By comparing lottery winners to those who played the lottery but didn’t win, they find that windfalls have no effect on the risk of being convicted for a crime or the risk of one’s children being convicted of a crime.

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Who Had Richer Parents, Doctors Or Artists? Quoctrung Bui and colleagues examine which jobs people with poor parents tend to have and which jobs people with rich parents tend to have. Analysing data from a large longitudinal survey in the US, they find that people with poor parents are most likely to work in farming, cleaning or childcare, while people with rich parents are most likely to work in science, law or finance.

Cross-Country Trends in Affective Polarization. Levi Boxell and colleagues examine trends in affective polarisation (the extent to which partisans feel negatively toward other parties) in twelve Western or Western-aligned countries. They find that there is no consistent trend: while polarisation has increased in the US and France, it has barely changed in Japan and Britain, and has actually fallen in Sweden and Germany.

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How Britain has become safer and scarier. Ben Sixsmith reconciles evidence that violent crime in Britain has fallen with the perception that the country has become more dangerous. He notes that mass stabbing events have become substantially more common, with no known cases prior to the 1990s. This helps to explain the discrepancy, he notes, because indiscriminate, sensational, public violence is uniquely disturbing.

Infrastructure Inequality: Who pays the cost of road roughness? Lindsey Currier and colleagues examine the roughness (or “bumpiness”) of American roads, using vertical acceleration data taken from the smartphones of Uber drivers. They find that vehicle speeds are slower on rougher roads, all else being equal, leading to social welfare losses. They also find that roads in poor and Black neighbourhoods are significantly rougher.

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Politically extreme individuals exhibit similar neural processing despite ideological differences. Daantje de Bruin and Oriel FeldmanHall study neurological responses to politically charged content in individuals with politically extreme views. Using a combination of methods, they find that such individuals exhibit similar neurological responses to politically charged content, regardless of whether they hold extreme left- or extreme right-wing views.

Can We Still Trust the Experts? The Siren Song of Influence. Cory Clark and Bo Winegard examine to what extent we should trust scientific experts. They argue that left-wing activism during the Great Awokening has greatly damaged public trust in scientific institutions. They also note that social media and an emphasis on “popularisation” have encouraged scientists to deviate from their core mission to seek out personal glory.

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Selection at the GSDMC locus in horses and its implications for human mobility. Xuexue Liu and colleagues look for signals of selection at 266 markers in the horse genome. They find a strong signal at the ZFPM1 locus, beginning around 5,000 years ago, and a strong signal at the GSDMC locus, beginning around 4,750 years ago. ZFPM1 is known to affect aggression, mood regulation and stress tolerance in mice, while GSDMC is known to affect anatomy.

Reevaluating the role of education on cognitive decline and brain aging in longitudinal cohorts across 33 Western countries. Anders Fjell and colleagues examine whether education protects against cognitive ageing. Analysing a large cross-national dataset of memory test scores, they find that while individuals with more education score higher at any given age, the rate at which scores decline does not vary by education.

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The decline in reading for pleasure over 20 years of the American Time Use Survey. Jessica Bone and colleagues examine over-time trends in reading for pleasure in the US. Analysing data from the American Time Use Survey from 2003 to 2023, they find that the percentage of Americans who read for pleasure declined substantially—from about 27% to about 17%. By contrast, the percentage of Americans who read with children did not change.

How Much Tax Do US Billionaires Pay? Evidence from Administrative Data. Akcan Balkir and colleagues examine how much tax US billionaires pay by matching data from the Forbes 400 to tax records. They find that the Forbes 400’s effective tax rate is around 24%, compared to 30% for all earners and 45% for top earners. The Forbes 400’s low effective tax rate is driven by low taxable income relative to total income (including unrealised gains).

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A book that changed my mind: ‘Manhood in the Making’. Drawing on evidence from anthropology, Rob Henderson argues that manhood is not a role that human males readily adopt—except in the presence of certain customs, rituals and rites of passage. He argues that if such customs are dismantled, as they have been to some extent in the West, men become increasingly lazy, apathetic and self-indulgent.

Do You Like Dogs, Cats, Both, or Neither? An Examination of Western Dating Site Users. Emil Kirkegaard examines what kinds of people prefer dogs versus cats. Analysing data from OKCupid, he finds that people who prefer dogs are higher in conservatism, mental health and number of children. Meanwhile, those who prefer cats are higher in intelligence. These associations persist when controlling for age, sex and education.

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