Women consistently showed higher concerns for Care, Fairness, & Purity in their moral judgements; sex differences in moral judgements were larger in individualist & gender-equal societies with more flexible social norms

Sex differences in moral judgements across 67 countries. Mohammad Atari, Mark H. C. Lai and Morteza Dehghani. Proceedings of the Royal Society B: Biological Sciences. October 21 2020. https://doi.org/10.1098/rspb.2020.1201

Rolf Degen's take: https://twitter.com/DegenRolf/status/1318822286921732101

Abstract: Most of the empirical research on sex differences and cultural variations in morality has relied on within-culture analyses or small-scale cross-cultural data. To further broaden the scientific understanding of sex differences in morality, the current research relies on two international samples to provide the first large-scale examination of sex differences in moral judgements nested within cultures. Using a sample from 67 countries (Study 1; n = 336 691), we found culturally variable sex differences in moral judgements, as conceptualized by Moral Foundations Theory. Women consistently scored higher than men on Care, Fairness, and Purity. By contrast, sex differences in Loyalty and Authority were negligible and highly variable across cultures. Country-level sex differences in moral judgements were also examined in relation to cultural, socioeconomic, and gender-equality indicators revealing that sex differences in moral judgements are larger in individualist, Western, and gender-equal societies. In Study 2 (19 countries; n = 11 969), these results were largely replicated using Bayesian multi-level modelling in a distinct sample. The findings were robust when incorporating cultural non-independence of countries into the models. Specifically, women consistently showed higher concerns for Care, Fairness, and Purity in their moral judgements than did men. Sex differences in moral judgements were larger in individualist and gender-equal societies with more flexible social norms. We discuss the implications of these findings for the ongoing debate about the origin of sex differences and cultural variations in moral judgements as well as theoretical and pragmatic implications for moral and evolutionary psychology.

4. General discussion

Given the pressing need for more conclusive empirical studies of sex differences in moral judgements, we examined women's and men's moral judgements using a high-powered design, and also investigated country-level correlates of sex differences in moral judgements in two consecutive studies. The current research is the first large-scale, cross-cultural investigation to empirically test multivariate sex differences in moral judgements nested within cultures. In Study 1, we examined the role of sex in moral judgements in 67 cultures using a large online sample. Further, in our country-level analysis, we examined the role of country-level cultural, socioeconomic, and gender-related indices in the magnitude of sex differences in moral judgements across cultures. In Study 2, we replicated these findings across 19 countries, by secondary analysis of completely independent data from locally administered, translated versions of the MFQ.

At the broadest level, Study 1 had three major findings: (i) three moral foundations of Care, Fairness, and Purity show systematic sex differences across cultures, with women scoring higher in all three cases, (ii) in more collectivist, non-WEIRD, and male-biased (higher sex ratio) cultures, sex differences in Care become smaller, and (iii) sex differences in Loyalty and Authority are quite variable across cultures. Relying on multivariate sex differences (i.e. Mahalanobis' D and its disattenuated bias-corrected statistic, see [27]) in moral judgements, the present multivariate effect sizes were found to be substantially larger than previously estimated sex differences in moral judgements (e.g. [3,34]) and the median effect size in individual differences research [65]. These multivariate effect sizes of sex differences were substantially larger in individualist and gender-equal countries. Study 2 largely replicated these findings. In particular, (i) women scored reliably higher than men on Care, Fairness, and Purity, (ii) sex differences in Care and Purity were substantially smaller in collectivist and male-biased (higher sex ratio) cultures, and (iii) sex differences in Loyalty and Authority were quite variable across cultures. These replicated findings support the notion that in more egalitarian Western (or Westernized) cultures, women and men tend to diverge in their Care concerns; and that in societies where the number of men for each woman is higher, sex differences in morality (particularly Care) drop substantially [4] which is consistent with the literature on sex ratio and its psychological implications [31]. In these contexts, men are more likely to focus on family values, long-term relationships, parenting, and caring for offspring since opportunities for short-term mating is scarce.

These culturally variable sex differences in moral foundations have implications for the origin of sex differences in psychology and evolutionary human sciences. First, the magnitude of sex differences, operationalized by multivariate (or global) difference effect size [33], was larger than previously thought, typically relying on univariate effect size, Cohen's d [3,66]. Second, these effects are considerably variable across cultural contexts, thus mono-cultural studies in research on sex differences can be misleading. For example, by looking at sex differences in Loyalty in the USA versus China, one would reach opposite conclusions. Third, these findings can be used to empirically compare (and refine) theoretical perspectives on culturally variable sex differences, hence contributing to a cumulative science of psychology of gender. Women's higher emphasis on Care and Purity judgements may be related to their parental care systems and disgust sensitivity, extensively researched in evolutionary psychology [67,68]. However, our findings regarding sex differences in Loyalty and Authority (i.e. negligible in size and highly variable across cultures) indicate that motivations for ingroup loyalty and hierarchical social structures are not substantially different between women and men across cultures. This finding is in line with evolutionary anthropological research examining sex differences in political leadership in small-scale egalitarian societies indicating that sex differences in leadership and coordination of ingroup members are not directly a product of differences in motivation for status and leadership, but an indirect product of sex differences in cooperation strategies, access to schooling, and sexual division of labour [69]. Furthermore, our results demonstrate that women and men value loyalty to their social networks and respecting authorities almost to the same extent; however, ‘social networks’ can mean different things for women and men. It is important to women to invest resources in creating and maintaining supportive social networks in order to protect themselves and their offspring [70]. For men, it can sometimes be attractive to invest their resources in forming coalitions to engage in intergroup aggression, as the spoils of an intergroup victory enhance their mating opportunities substantially [71]. Thus, men might be keener than women to take on leadership roles during intergroup competitions. In the case of Loyalty and Authority (which show large cultural variability in sex differences, from men scoring higher than women, to no difference, to women scoring higher than men), cultural evolution can be the key driving force which accounts for the diversity of cultural norms among populations. Cultural evolution is typically ‘faster’ than biological evolution and can be spread in a population in very few generations. It has been suggested that the legal and political systems that govern societies are themselves outcomes of cultural evolution [72,73], as it has eventuated over human history.

With regard to cultural variation of sex differences based on cultural, socioeconomic, and gender-related variables, the findings suggested that women and men are more different in their moral judgements in gender-egalitarian societies compared with less egalitarian ones. Notably, however, these results cannot be used to infer any causal relationships between gender equality and the magnitude of sex differences since the data are cross-sectional. Even in countries with gender-equal outcomes (high Gender Gap Index), where women and men have equal access to health and education, entrenched gender norms about moral phenomena persist. Moreover, these findings tell us nothing about individuals' experience of gender inequality and their moral judgements [44]. These findings are consistent with evolutionary psychological research on sex differences across cultures. These results, on the other hand, are in contrast with the original predictions of the social role theory [21]. Notably, social role theory has explicitly incorporated cultural evolutionary components into the theory [20], advocating that ‘biological characteristics affect the efficient performance of many activities in society, they underlie central tendencies in the division of labour’. However, this theory's prediction of women and men being more similar in gender-egalitarian societies was not supported here.

Of note, while the present work is not a test of MFT itself, the theoretical limitations of MFT should be noted. MFT's evolutionary roots have been argued to be ad hoc rather than theory-driven. While Graham et al. [7] provide an evolutionary function for each of the foundations, the theory itself has been developed without a clear a priori evolutionary model. The theory of ‘morality-as-cooperation’ [74], for example, argues that morality consists of a collection of biological and cultural solutions to the problems of cooperation recurrent in humans' evolutionary history, proposing seven moral domains (family, group, reciprocity, heroism, deference, fairness, and property) which are considered morally good across cultural contexts [74]. Future research is encouraged to replicate and extend the present findings using modern evolutionary theories of morality using corresponding measures [75]. In addition, MFQ has limitations. MFQ measures a pre-specified set of features that are relevant for moral judgement. More specifically, this questionnaire focuses on abstract judgements about what is part of the moral domain, rather than direct moral decision-making. Another limitation of the present studies is their samples. Study 1's sample is a convenience sample from an online platform and Study 2 is a secondary analysis of different samples coming from a relatively heterogeneous set of countries, collected using different procedures. Hence, future studies are encouraged to replicate these findings using more representative sampling procedures across diverse sets of cultures, including small-scale societies.