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There is evidence that the Flynn Effect is plateauing or even reversing in many Western countries, while it is still found in many developing countries. In order to understand the causes of these differences, as well as the Flynn Effect as such, data from diverse samples are needed. Here, we compare two similar and representative samples of schoolchildren with an average age of 12 years from the Saudi capital of Riyadh, tested in 2004 and 2018. We find that the test performance was higher in 2018, corresponding to 6.6 IQ points. We suggest that this represents part of a long-term Flynn Effect caused by broad societal changes, having considered other feasible explanations such as internal migration patterns or reforms in education policy.

Alcohol impairs motor performance, but it remains unclear precisely why this is the case. Here, we examine the effects of alcohol intoxication on conditioned eyeblink responses, a form of classical conditioning dependent on the cerebellum. In experiment 1, the conditioned responses of 18 students before and after alcohol consumption up to 1 ‰ were compared against the performance of 26 non-drinking controls. In experiment 2, 17 students were tested repeatedly at increasing blood alcohol levels up to 1 ‰. The results reveal a gradual decrease in both the percentage and timing of conditioned responses following alcohol consumption, with pronounced impairments emerging at blood alcohol content levels exceeding 0.5 ‰. These findings are consistent with the idea that the motor deficits associated with alcohol consumption are linked to effects on the cerebellum.

We make the case that Bird, Jackson Jr., and Winston's (BJ&W; 2024) policy proposals boil down to a rejection of Merton's (1942) traditional scientific norms of communality, universalism, disinterestedness, and organized skepticism, and a demand for anti-Mertonian norms to be imposed, top down, upon psychological science. Their anti-Mertonian norms (specifically secrecy, particularism, interestedness, and organized dogmatism) are at odds with the scientific ethos. We highlight problems with their argument that Racial Hereditarian Research (RHR) is uniquely "socially pernicious". We then discuss adverse effects that their imposition of anti-Mertonian norms would likely cause in relation to: 1) instances of research on racial and ethnic differences that have produced findings agreeable to egalitarianism, and which would be proscribed under their framework; 2) the fomenting of genuinely scientifically racist beliefs that are empirically at odds with RHR; and 3) the chilling effect on other areas of science whose findings have also been misused, including “mainstream human genetics”. Ultimately, we observe that BJ&W's anti-Mertonian policy prescriptions are unworkable in practice, and would be highly damaging to psychological science if widely enforced.

Bird, Jackson Jr., and Winston (BJ&W; 2024) argue that a “racial hereditarian research” (RHR) program exists, is prominently represented in academic literature, and is socially harmful as it supports “scientific racism” and emboldens the far-right. Consequently, drastic steps should be taken by the American Psychological Association to curb its production. They support these claims with a bibliography of alleged RHR publications and other outputs appearing from 2012 on. To determine the validity of their claims, we conducted a content meta-analysis of the 268 peer-reviewed articles (excluding editorials, book reviews, etc.) listed in Section 1 of their bibliography. These were independently rated using the following dimensions (as explicated by BJ&W): (1) use of “folk” racial categories; (2) biological race realism; (3) claims that differences between “races” are due to selection and/or genetic factors - these being the core of BJ&W's definition of RHR. Additional criteria were: (4) discussion of racial “proxy” categories (e.g., nations); and (5) degree of interest shown in the articles by one White nationalist publication. Inter-rater reliability was acceptable (ICC3,k = 0.711, 95% CI = 0.633, 0.773). A Content factor was identified among the averaged ratings exhibiting strong positive loadings for 1, 2, and 3 (indicating an RHR program), but a significant negative loading for 4 (indicating that nations, etc. tend not to be employed as racial proxies, but are typically used rather than race in such studies), and a null loading for 5. The last result (along with consideration of data presented elsewhere in the bibliography) counteracts the idea that RHR constitutes “scientific racism”, or supports White nationalism. Only 23 % of the publications unambiguously (based on 100 % convergence between raters for 1, 2, and 3) qualify as RHR, with the plurality (37 %) appearing in one niche journal, consistent with strong scientific taboos against RHR. Moreover, 30% of the publications unambiguously had nothing to do with RHR. BJ&W's characterisation of their bibliography as evidencing wide scale “scientific racism” is therefore not compellingly supported by its contents.

Many conservative public figures have claimed that Google Search exhibits a liberal bias in the links presented. Surprisingly, perhaps, the few scientific studies conducted so far have tended to support this claim. In the study reported here, we compared Google search engine result pages (SERPs) for 8 terms related to immigration across 8 geographically distinct locations (municipalities). For each term, the top 30 generated search results were collected and rated by 5 independent evaluators in terms of (1) attitude towards immigration and (2) level of politicisation. Overall, the attitude toward immigration in returned search results was significantly positive, although the positive links tended to appear at somewhat lower positions in the list of search results. While most links were non-political, political links, too, tended to appear at lower positions, although the effect was minor. Both attitude and politicisation of SERPs varied considerably with the specific search term used. We did not find evidence for a location-induced bias, as the SERPs for different municipalities contained essentially the same links, albeit in somewhat different order. While the observed immigration-positive tendency itself may appear to fuel filter bubble concerns, the matter turns out to be complex. We identify the need for more research on several key issues.

Sorjonen et al. (2024) critique a recently published finding that cognitive tilts are heritable, which was advanced as a line of evidence supporting their substantive (rather than artefactual) nature. These researchers claim: i) that the heritability of tilts is simply a function of the heritabilities of the specific cognitive dimensions used in their estimation, and ii) that spuriously heritable tilts can be recovered using difference scores between psychometric, anthropometric, and even random number variables. Here, multiple studies employing three behavior genetic datasets are used to test these claims. Even when cognitive tilts are residualized for their association with their constituent abilities, they still exhibit small, but non-zero heritabilities. Shared environmentality (C) accounts for the largest proportion of variance among these residuals. Tilts generated using random numbers are, by contrast, in all cases associated with AE models, exhibiting near 100 % E variance, corresponding to error. In the Swedish Twin Registry, the tilt residual is positively correlated with a measure of life history speed (Mini-K score), suggesting that tilts capture cognitive differentiation-integration effort conditioned developmentally by C variance. Distinct latent factors among psychometric and anthropometric variables in the Georgia Twin Study are also found. These indicate the presence of distinct developmental modules, meaning that tilts estimated using manifest variables associated with different modules lack theoretical credibility, as also evidenced by weak cross loadings.

Sex differences in human performance have been documented across a wide array of human endeavours. Males tend to exhibit higher performance in intellectually demanding and competitive domains, and this difference tends to be more pronounced the higher the level of performance. Here, we analyse publishing performance for the whole population of associate and full professors in relatively sex-balanced disciplines, namely Education, Nursing and Caring Science, Psychology, Public Health, Sociology, and Social Work, comprising 426 women and 562 men. We find that sex differences in the number of publications, citations, and citations per publication were small across low and medium levels of productivity, but become more pronounced the higher the level of performance. In the top performing 10% the female proportion decreases from the average 43.2% to 26% (25 F, 71 M), which further decreases to 15% in the top 5%. The results are discussed with respect to the greater male variability hypothesis, sex differences in psychological traits, and environmental factors such as sex discrimination.

It is commonly assumed that personalization technologies used by Google for the purpose of tailoring search results for individual users create filter bubbles, which reinforce users’ political views. Surprisingly, empirical evidence for a personalization-induced filter bubble has not been forthcoming. Here, we investigate whether filter bubbles may result instead from a searcher’s choice of search queries. In the first experiment, participants rated the left-right leaning of 48 queries (search strings), 6 for each of 8 topics (abortion, benefits, climate change, sex equality, immigration, nuclear family, Islam, and taxation). An independent sample of participants were then asked to select one of these queries for each of the 8 topics. With the exception of the topic of Islam, participants were significantly more likely to select a query corresponding to their own political leaning, compared to other queries, explaining between 12% and 39% of the variance. A second experiment investigated the effect of the political leaning of the same queries on the overall political leaning of Search Engine Result Pages (SERPs) in Google Search. The top six results of each SERP were rated collectively by a third group of participants, explaining 36.3% of the variance across all 48 search terms (p <.00001). That is, (1) participants in our experiments tended to select own-side search queries, and (2) using those queries tended to yield own-side search results when using the Google search engine. Our results are consistent with the notion of a self-imposed filter bubble in which query selection plays a salient role.

Background: Understanding individual differences in psychology, and how they relate to specific addictions, may allow society to better identify those at most risk and even enact policies to ameliorate them. Internet addiction is a growing health concern, a research focus of which is to understand individual differences and the psychology of those most susceptible to developing it. Western countries are strongly overrepresented in this regard.

Method: Here, sex and national differences in internet addiction are measured, using Young's ‘Internet Addiction Test,’ in two non-Western countries, Egypt and Saudi Arabia. >800 students aged 18 and 35 years (M = 20.65, SD = 1.48) completed a multidimensional internet addiction instrument. The instrument measures traits such as Withdrawal and Social Problems, Time Management and Performance and Reality Substitute.

Results: Analyses revealed that males scored higher than females and Saudis higher than Egyptians on nearly all scales, including the total score. Factor analysis of the 20-item instrument revealed three factors, all exhibiting sex and culture differences.

Conclusions: These findings add to the body of evidence that males are higher than females in problematic internet use, as they are in addictive behaviors in general. Our findings may also imply that restrictions on male-female interaction, which are more pronounced in Saudi Arabia, may elevate the prevalence of internet addiction. The internet is also easier and cheaper to access in Saudi Arabia than in Egypt.

Attention deficit hyperactivity disorder (ADHD) is the most prevalent neuropsychiatric disorder in the world. Currently, the diagnosis is based mainly on interviews, resulting in uncertainties in the clinical assessment. While some neuropsychological tests are used, their specificity and selectivity are low, and more reliable biomarkers are desirable. Previous research indicates that ADHD is associated with morphological changes in the cerebellum, which is essential for motor ability and timing. Here, we compared 29 children diagnosed with ADHD to 96 age-matched controls on prism adaptation, eyeblink conditioning, and timed motor performance in a finger tapping task. Prism adaptation and timing precision in the finger tapping task, but not performance on eyeblink conditioning, differed between the ADHD and control groups, as well as between children with and without Deficits in Attention, Motor control, and Perception (DAMP) – a more severe form of ADHD. The results suggest finger tapping can be used as a cheap, objective, and unbiased biomarker to complement current diagnostic procedures.