Sex and age differences in "theory of mind" across 57 countries using the English version of the "Reading the Mind in the Eyes" Test

Abstract

The "Reading the Mind in the Eyes" Test (Eyes Test) is a widely used assessment of "theory of mind." The NIMH Research Domain Criteria recommends it as one of two tests for "understanding mental states." Previous studies have demonstrated an on-average female advantage on the Eyes Test. However, it is unknown whether this female advantage exists across the lifespan and across a large number of countries. Thus, we tested sex and age differences using the English version of the Eyes Test in adolescents and adults across 57 countries. We also tested for associations with sociodemographic and cognitive/personality factors. We leveraged one discovery dataset (N = 305,726) and three validation datasets (Ns = 642; 5,284; and 1,087). The results show that: i) there is a replicable on-average female advantage in performance on the Eyes Test; ii) performance increases through adolescence and shallowly declines across adulthood; iii) the on-average female advantage is evident across the lifespan; iv) there is a significant on-average female advantage in 36 out of 57 countries; v) there is a significant on-average female advantage on translated (non-English) versions of the Eyes Test in 12 out of 16 countries, as confirmed by a systematic review; vi) D-scores, or empathizing-systemizing, predict Eyes Test performance above and beyond sex differences; and vii) the female advantage is negatively linked to "prosperity" and "autonomy," and positively linked to "collectivism," as confirmed by exploratory country-level analyses. We conclude that the on-average female advantage on the Eyes Test is observed across ages and most countries.

Keywords: age differences; cognitive empathy; cross-cultural; reading the mind in the eyes; sex differences.

Fig. 1.

Schematic overview of the study. In this study, we investigated three major questions. Are there on-average sex differences on the Eyes Test; are there on-average age differences on the Eyes Test; and do the on-average sex differences, if any, appear across countries? These three questions are represented by large bold font. We also asked secondary questions: what are the sociodemographic or cognitive/personality factors associated with scores on the Eyes Test and what are the country-level variables (PESH indicators) associated with country-level sex differences on the Eyes Test? Data used to address the former question (including D-scores, Big Five personality traits, education, income) are represented in smaller nonbold font. PESH indicators are not visualized in this diagram. For each question, the primary dataset was the discovery dataset from Lab in the Wild (blue box). We used three validation datasets to validate and extend the results—validation dataset A from Cambridge Psychology (red box), validation dataset B from Musical Universe (purple box), and validation dataset C from Musical Universe (green box). If an arrow appears to go through/underneath a box, then the variable in the box is not included in the specified dataset of the arrow, which can be discerned by the color of the arrow.

Fig. 2.

Sex differences on the English version of the Eyes Test across the discovery and validation datasets. Each plot displays the conditional effects of sex (population-level predictor) with 95% credible intervals. As can be seen, there is evidence for an on-average female advantage in each of the four datasets.

Fig. 3.

The effect of sex on the English version of the Eyes Test in each of the 57 countries in the discovery dataset. Beta values with 95% credible intervals from multilevel Bayesian analysis are plotted for each of the 57 countries. Beta values above 0 indicate a descriptive female advantage and beta values below 0 indicate a male advantage. As can be seen, 36 countries have a lower interval bound ≥ 0, indicating a female advantage, while no countries have a higher interval bound ≤ 0, which would indicate a male advantage.

Fig. 4.

Geographic distribution of ω_t for the English version of the Eyes Test across 57 countries. This figure displays ωt for each of the 57 countries observed in the discovery dataset. Lightened yellow colors indicate lower values while darker red colors indicate higher values.

Fig. 5.

Mean scores on the English version of the Eyes Test by age and sex in the discovery dataset. This figure visualizes the results from the constrained nonlinear regression analysis performed separately for females and males. Results are age and sex differences in Eyes Test scores from 16 to 70 y of age. The figure also identifies inflection points in performance across this age range. Average scores and associated 95% confidence intervals are charted for females and males at each age year.

Fig. 6.

An item from the “Reading the Mind in the Eyes” Test. The photograph in this figure is from item 19 of the Eyes Test. Underneath the photograph are four answer choices: arrogant, grateful, sarcastic, and tentative. The correct answer is tentative.