2.1. Prioritising diversity

Our first proposition is a concerted commitment to diversifying perspectives and methods in order to innovate the field, achieve ethical research practice and foster more fruitful dialogue with neighbouring social sciences. It is now widely accepted that improving the representation of minoritised and underrepresented groups is not only essential from a social justice perspective, but also leads to critical intellectual shifts that improve scholarship (AlShebli et al., Reference AlShebli, Rahwan and Woon2018; Bolnick et al., Reference Bolnick, Smith and Fuentes2019). As we have highlighted above, the increased representation of women in evolutionary social science illustrates this point well, with women continuing to lead the charge in tackling gender stereotypes and studying women's adaptive strategies (e.g. Borgerhoff Mulder, Reference Borgerhoff Mulder, Burger, Lee and Searin press; Fox et al., Reference Fox, Scelza, Silk and Kramer2023; Mace, Reference Mace2013; Scelza, Reference Scelza2013; Sear, Reference Sear2021). Appropriately, this volume is dominated by women authors.

While barriers to gender equality in science remain (e.g. Fox et al., Reference Fox, Duffy, Fairbairn and Meyer2019; Heidt, Reference Heidt2023), we must be attentive to inclusion of other underrepresented groups. Here we turn our focus to achieving representation from varied cultural backgrounds, particularly from scholars from outside of Europe, North America and other relatively high-income regions (see also Mughogho et al., Reference Mughogho, Adhiambo and Forscher2023; Urassa et al., Reference Urassa, Lawson, Wamoyi, Gurmu, Gibson, Madhivanan and Placek2021). This is critical for several reasons. First, there can only be limitations from excluding researchers with a wider array of life experiences. Not least, it limits our collective capacity to avoid ethnocentric bias. Second, while low and middle-income countries (LMICs) by no means have a monopoly on gender inequality, they also experience the greatest disparities in health, education and apparent bargaining power between women and men (Jayachandran, Reference Jayachandran2015). Gender inequality is now a major focus of global health research and policy. It is only appropriate then that LMIC scholars are represented. Finally, in both global health (The Lancet Global Health, 2018) and cross-cultural social science, including anthropology, psychology and economics (Urassa et al., Reference Urassa, Lawson, Wamoyi, Gurmu, Gibson, Madhivanan and Placek2021), ‘parachute’ and ‘parasitic’ research practices remain commonplace. Too often, research is conducted in LMICs by visiting researchers (i.e. of a different nationality/cultural background to the study population) without collaboration with local communities, researchers and research institutions, or collaboration occurs but is undervalued and uncredited.

In an effort to address these issues, we purposely sought out contributions led by authors from LMICs (Akurugu et al., Reference Akurugu, Dery and Bata2022; Baraka et al., Reference Baraka, Lawson, Schaffnit, Wamoyi and Urassa2022; He et al., Reference He, Rui, Zhang, Tao, Wu, Mace and Ji2022), or where research is conducted in LMICs in collaboration and co-authorship with research institutions and/or scholars of the same nationality/cultural background as the study participants (Agey et al., Reference Agey, Crippen, Wells and Upreti2023; Mattison et al., Reference Mattison, MacLaren, Sum, Mattison, Liu, Shenk and Wander2023; Schaffnit et al., Reference Schaffnit, Page, Lynch, Spake, Sear, Sosis and Shenk2023). We also asked all contributors to consider the criteria they used for authorship decisions, referring them to Morton et al.'s (Reference Morton, Vercueil, Masekela, Heinz, Reimer, Saleh and Oriyo2022) guidelines on promoting equitable authorship (including avoidance of ‘token’ authorship). To minimise bias in the review process, we assigned papers to at least one peer reviewer from the same country or world region as the population under study. Nevertheless, inequalities remain apparent. Most notably, in only one paper using data from an LMIC are all authors of the same nationality as the population studied (Akurugu et al., Reference Akurugu, Dery and Bata2022). Diversity was also lost across the development of the special collection; several contributions were rejected after peer review or because invited authors ultimately opted to submit their manuscript elsewhere. These dynamics surely attest to the barriers faced by LMIC scholars and limited incentives for engaging with a field that may not presently share the same priorities. To round out the collection, we then added several previously published papers addressing sexual/gendered conflict (Kerry et al., Reference Kerry, Blake, Murray and Brooks2021; Lawson et al., Reference Lawson, Schaffnit, Kilgallen, Kumogola, Galura and Urassa2021b; Snopkowski & Nelson, Reference Snopkowski and Nelson2021; Starkweather et al., Reference Starkweather, Shenk and McElreath2020).

Akurugu et al. (Reference Akurugu, Dery and Bata2022) exemplify the value of diversifying perspectives in their article on bridewealth, i.e. a transfer of capital from the groom's to the bride's family. Bridewealth is typically framed as harmful to women, for which there is solid evidence. For example, using a vignette experiment wherein the completeness of bridewealth payments is manipulated, Horne et al. (Reference Horne, Dodoo and Dodoo2013) convincingly document a link between bridewealth and normative constraints on women's reproductive autonomy. Reviewing the wider literature, Akurugu and colleagues counter that the ‘foreign gaze’ (see Abimbola, Reference Abimbola2019) of most scholarship on bridewealth is characterised by unsettling generalisations and stereotypes, such as labelling bridewealth-practising groups as ‘primitive’ or assuming a priori that bridewealth is inherently harmful to women. Drawing on their ethnographic work in Ghana (Akurugu et al., Reference Akurugu, Domapielle and Jatoe2021), they counter that, when considered as part of wider patriarchal context that limits women's empowerment more broadly, bridewealth serves a critical purpose in legitimising relationships and the associated rights of women and children from the marriage. As such, women frequently attest support for bridewealth and abolishing the practice may only worsen their status. Akurugu et al. (Reference Akurugu, Dery and Bata2022) also make the novel contribution of suggesting that conflicts of interest over women's autonomy may be best settled by empowering overlooked indigenous systems, such as the use of traditional courts to address marital disputes.

We also showcase methodological diversity. Several papers utilise qualitative approaches (Agey et al., Reference Agey, Crippen, Wells and Upreti2023; Akurugu et al., Reference Akurugu, Dery and Bata2022; Baraka et al., Reference Baraka, Lawson, Schaffnit, Wamoyi and Urassa2022), rarely at the forefront of contemporary evolutionary social science. Baraka et al. (Reference Baraka, Lawson, Schaffnit, Wamoyi and Urassa2022) demonstrate the value of mixed methods research in their study of Tanzanian marriages. Global health frameworks characterise marriages under 18 years as harmful ‘child marriages' serving the interests of parents (e.g. through a larger bridewealth or smaller dowry), and/or husbands who prefer younger wives, while brides pay only costs (e.g. greater risk of pregnancy complications, IPV and school dropout). In earlier work by the same team, testing these assumptions using quantitative data on partner preferences, bridewealth and women's wellbeing and reproductive success led to only limited support (Lawson et al., Reference Lawson, Schaffnit, Hassan and Urassa2021a; Schaffnit et al., Reference Schaffnit, Hassan, Urassa and Lawson2019). In particular, marriage under 18 years held mixed, rather than purely negative, relationships with the well-being of adolescent girls and young women, and was associated with higher reproductive success. Baraka et al. (Reference Baraka, Lawson, Schaffnit, Wamoyi and Urassa2022), through analysis of focus groups and in-depth interviews, also reject parent–offspring conflict as a primary driving force behind early marriage. Community members believed that remaining unmarried did not shield adolescent girls from risky sexual behaviour and that early marriage often provides relative social and economic security. However, support for gendered conflict was stronger; some adolescent girls were described as being lured into unstable early marriages by men misrepresenting their long-term intentions. This marital scenario may have been previously overlooked because (a) such ‘trick’ marriages only represent a fraction of marriages in the community, such that their costs are masked when analysed alongside relatively neutral or advantageous marital scenarios, and (b) naive assumptions that a gendered conflict model requires active coercion. Here, adolescent girls entered marriages willingly, sometimes against parental wishes, but later came to regret the decision when the marriage failed to meet their expectations.

Anderson and Bidner (Reference Anderson and Bidner2022) further address what may be gained by embracing the overlapping concerns of economics and evolutionary social science, taking polygynous marriage as a case study. Indeed, it is striking how much recent scholarship in economics addresses cultural variation in conflict between women and men, often drawing heavily on classic anthropological scholarship for theoretical inspiration. For example, recent papers address the role of not only marriage practices (Anderson & Bidner, Reference Anderson and Bidner2022), but also contemporary and historical modes of subsistence (e.g. Alesina et al., Reference Alesina, Giuliano and Nunn2013; Becker, Reference Becker2019; Hansen et al., Reference Hansen, Jensen and Skovsgaard2015) and kinship systems (Lowes, Reference Lowes2020) in determining gender inequality. As we argue below, there is also much to gain from boosting engagement with neighbouring research traditions, both non-evolutionary and evolutionary, that emphasise the role of culture in determining behavioural diversity.

2.2. Emphasis on culture

Our second proposition is a more forceful recognition of the role of culture in the expression of human sex/gender roles and accompanying conflict between women and men. This call is not novel, with the importance of integrating cultural forces into evolutionary models emphasised by Smuts (Reference Smuts1992, Reference Smuts1995), Borgerhoff Mulder and Rauch (Reference Borgerhoff Mulder and Rauch2009) and many others (e.g. Wood & Eagly, Reference Wood and Eagly2012). However, we propose that scholarship needs to be much more intentional in addressing the role of inherited cultural practices, normative sanctions and evolved social learning mechanisms in structuring conflict battlegrounds and conflict resolution. To encourage this priority, we propose a strategic shift in terminology from ‘sexual conflict’ to ‘gendered conflict’ when addressing human behaviour. This corresponds to the common usage of ‘sex’ as emphasising differing chromosomes, and external genitals, which typically serve as the basis for sex assignment at birth, and ‘gender’ as emphasising societal norms and expectations of behaviour, and personal identification (for a discussion of alternative definitions of sex and gender, and their limitations, see Hyde et al., Reference Hyde, Bigler, Joel, Tate and van Anders2019; Muehlenhard & Peterson, Reference Muehlenhard and Peterson2011). An emphasis on culture does not negate that conflict at an evolutionary level ultimately plays out via differential selection on biological sexes. However, emphasising gender over sex places appropriate focus on how the behaviour of women and men is also fundamentally socially acquired and transmitted.

More than steer the direction of research, our proposed change in terminology reinforces two foundational points, particularly with respect to how our research is (mis)understood by researchers working outside of the evolutionary human sciences. First, by embracing the term gender, and its connotation with social and cultural influences, we make immediately clear that such influences do not sit outside of the scope of an evolutionary perspective. Likewise, we steer folks away from the stubborn assumption, associated with the connotations of ‘sex’, that an evolutionary perspective dictates that differences between women and men can, or should, be essentialised to chromosomes, hormones or other ‘biological’ essences (for discussions of the false nature-nurture, biological–cultural/social dichotomy see Eagly & Wood, Reference Eagly and Wood2013; Nettle, Reference Nettle2009, Reference Nettle2018). Second, adopting a distinct terminology for humans and nonhuman behaviour, we reinforce acknowledgement of fundamental differences between these taxonomic groupings, particularly our propensity for complex cumulative culture (Mesoudi & Thornton, Reference Mesoudi and Thornton2018). Making this distinction explicit will hopefully instil appropriate caution in researchers when applying theory based on non-human animals to humans.

To draw greater attention to cultural forces, Table 1 highlights findings from recent and classic scholarship on a range of relevant practices that structure gendered conflict, including articles from this collection and research carried out by scholars working outside of evolutionary social science. Each practice can be considered cultural because associated behaviours are acquired socially, such that women and men's behaviour in large part reflects a matter of tradition rather than preferences required by individual learning, and the costs and benefits of associated behaviours are modified by normative sanctions, i.e. rewards for compliance and/or punishments for deviation. Note that here we have purposely highlighted potentially contrary findings that could be interpreted as indicating that a practice is, or is not, a site of gendered conflict (and so harmful to one gender or both). In many cases, the impacts on women and men, and the relevant selective forces at stake, remain subject to debate.

Table 1. Cultural practices structure gendered conflict. Conflict between women and men is influenced by cultural context; relevant behaviours are acquired socially and influenced by normative sanctions. However, there remains much debate about the extent to which certain cultural practices impact fitness and wellbeing. Here, we highlight examples of, sometimes contrasting, findings across the literature on the potential costs and/or benefits of a range of cultural practices, including work by both evolutionary and non-evolutionary social scientists. These examples are not intended to be fully representative, but rather illustrative of the diversity of existing scholarship.

In considering these practices, one important goal then is to interrogate alternative hypotheses about who, if anyone, gains (in an ultimate and proximate sense) from relevant practices and how. Howard and Gibson (Reference Howard and Gibson2023), for example, test hypotheses that IPV, which varies widely in prevalence and has a strong normative component, reflects a male strategy to (a) reduce perceived threats to their paternity certainty, (b) impose a higher fertility optimum than their partners via coercive sexual activity and/or (c) to quell spousal objections to diverting resources outside of the family (see also Stieglitz et al., Reference Stieglitz, Kaplan, Gurven, Winking and Tayo2011). Utilising proxies for anticipated levels of paternity certainty, contrasting fertility preferences and extra-marital relationships in African national survey data, they conclude that patterns are most consistent with paternity uncertainty risk and paternal disinvestment hypotheses. They also highlight limitations to their analysis, including ambiguity in causal relationships between covariates included in their models, stifling capacity for causal inference. We suggest that future research must also recognise that an absence of IPV need not equate with a lack of conflict. Indeed, women who do not challenge male dominance (e.g. never oppose men's investments outside of marriage) because of an anticipated threat of IPV or other harmful consequences may suffer the largest conflict load, with IPV incidence itself consequently more reflective of situations were women have sufficient bargaining power to make challenging male authority a worthwhile risk (see Kilgallen et al., Reference Kilgallen, Schaffnit, Kumogola, Galura, Urassa and Lawson2022).

A second overarching goal is to understand why relevant cultural practices vary across time and space. This can be considered an exercise in elucidating the ‘evolutionary and ecological roots’ of gender inequality (see also Kaplan et al., Reference Kaplan, Hooper and Gurven2009), as we work to identify legacies of selection and adaptation in response to interrelated socioecological factors such as mode of subsistence, mortality risks, sex ratio, population density and intergroup relationships. It is important to note here that emphasising socioecological contingency in this way does not equate with assuming genetic adaptation to particular socioecological conditions, but rather envisages humans as bestowed with a remarkable capacity for adaptive phenotypic plasticity (Nettle et al., Reference Nettle, Gibson, Lawson and Sear2013). Indeed, a one-to-one matching between any single socioecological factor and appropriate behavioural response is unlikely, with adaptive strategies depending on the overall constellation of factors defining a context. Further complicating matters, once a cultural practice becomes entrenched, it may further influence patterns of selection on other behaviours.

Scelza et al. (Reference Scelza, Prall and Starkweather2021) expertly illustrates this complexity with respect to pastoralism, which typically requires long periods of spousal separation with men transporting livestock to feed away from home. Such absences may ultimately favour social norms that limit women's freedom, so as to ensure confidence of paternity. Supporting this notion, Becker (Reference Becker2019) has documented that women from historically pastoral societies are more likely to have undergone the most invasive forms of female genital mutilation/cutting (FGMC) and adhere to restrictive norms about women's sexual freedom and mobility. However, there are exceptions to this pattern, such as the Himba of Nambia, who combine pastoralism with strong norms promoting women's sexual autonomy. Scelza et al. (Reference Scelza, Prall and Starkweather2021) speculate that a combination of factors explains Himba exceptionalism, including a history of matrilineal inheritance predating pastoralism, bestowing the Himba with norms favouring sexual freedom for both genders, and both a high reliance on children's labour and a female-biased adult sex ratio, which ultimately allows men to more easily compensate for paternity loss through pursuit of their own extra-marital partnerships.

Modelling the role of cultural history, such as the legacy of matriliny in the above example, presents a particular challenge because it requires more information than can be gained from observing a population at any single time point. Indeed, this challenge applies broadly to optimality models of human behaviour (Barrett & Stulp, Reference Barrett and Stulp2013). One tool at our disposal is phylogenetic analysis, which can be used to examine how transitions from one cultural state predicts changes in others (Mace & Jordan, Reference Mace and Jordan2011). Work in this tradition, for example, has addressed origins and patterns of change in the practice both female and male genital mutilation/cutting (Šaffa et al., Reference Šaffa, Zrzavý and Duda2022), polygynous marriage (Minocher et al., Reference Minocher, Duda and Jaeggi2019), the direction of marriage payments (Fortunato et al., Reference Fortunato, Holden and Mace2006) and traditions of sex-biased dispersal, i.e. post-marital residence (Ji et al., Reference Ji, Zhang, Pagel and Mace2022; Jordan et al., Reference Jordan, Gray, Greenhill and Mace2009). More generally, these considerations make clear that a robust evolutionary approach to human diversity requires investing in a bedrock of historical and ethnographic knowledge.

At the proximate level, there is also still much to learn about the role of evolved mechanisms of social learning in determining gender ideology (i.e. expectations about appropriate behaviour for each sex/gender). Here, the paucity of evolutionary research is jarring, not least because the notion of socially acquired and ‘performed’ gender roles has motivated a large body of scholarship in sociology and social psychology (Butler, Reference Butler1988; Morgenroth & Ryan, Reference Morgenroth and Ryan2018). Instead, evolutionary scholars studying social learning strategies have devoted their attention to alternative behavioural domains, most obviously cooperative tendencies (Henrich & Muthukrishna, Reference Henrich and Muthukrishna2021) and, to a lesser extent, reproductive scheduling (Colleran, Reference Colleran2016). Outside of evolutionary social science, many studies convincingly demonstrate a pivotal role of social learning in gendered conflict. Bursztyn et al. (Reference Bursztyn, González and Yanagizawa-Drott2020), for instance, demonstrate the power of conformity bias: they find that Saudi men underestimate peer support for women's empowerment and that correcting these misperceptions leads to shifts in gender relations, e.g. men becoming more supportive of their wives working outside the home. Swindle (Reference Swindlen.d.) addresses pathways of cultural diffusion in Malawi, linking exposure to journalism critically covering IPV with the probability that surveyed men condemn violence. Cano and Hofmeister (Reference Cano and Hofmeister2023) consider the vertical transmission of gender norms, demonstrating that, even when controlling for potential confounders, observation of paternal involvement in domestic labour is predictive of Australian adolescents later adopting more equalitarian gender ideology. These examples also lead into our final proposition: evolutionary studies of gendered conflict have much untapped potential to contribute to areas of contemporary policy concern.

2.3. Tackling areas of policy concern

There is much scope for evolutionary perspectives not only to contribute to our understanding of patriarchy, but also to provide fresh insights into how gendered conflict and its harmful impacts may be reduced worldwide. As such, our third proposition is that we target topics of contemporary policy concern. There are notable synergies with our first two priorities here. Committing to diversity guards against ethnocentric bias, increasing the likelihood of generating culturally sensitive policy recommendations. Elucidating the role of culture also offers new possibilities for engagement with global health professionals working on gender inequality, whose attention focuses increasingly on tackling inequitable social norms (Jayachandran, Reference Jayachandran2020). Indeed, the now popular ‘social norms approach’ to behaviour change interventions (see Bicchieri & Mercier, Reference Bicchieri and Mercier2014) has much inherent overlap with contemporary approaches to cultural evolution. Most obviously, both share assumptions that behaviour is influenced by perceptions of what others do and believe, and the anticipated rewards or punishments for conforming to, or deviating from, prevailing norms (Eriksson et al., Reference Eriksson, Strimling, Gelfand, Wu, Abernathy, Akotia and van Lange2021; Kendal et al., Reference Kendal, Boogert, Rendell, Laland, Webster and Jones2018).

Several relevant themes emerge in the special collection. The first is the wellbeing consequences of so-called ‘harmful cultural practices’. Since the 1990s, the United Nations and other international development agencies have identified cultural practices as a fundamental determinant of gender inequality, with particular focus on traditions of son preference, IPV, FGMC, polygynous marriage, ‘child marriage’ (<18 years), forced or arranged marriage, bride caputre/kidnapping, bridewealth and dowry (Longman & Bradley, Reference Longman and Bradley2016), but also less well-known practices such as ‘breast ironing’ (Amahazion, Reference Amahazion2021), and ‘widow cleansing’ (Perry et al., Reference Perry, Oluoch, Agot, Taylor, Onyango, Ouma and Corneli2014; Manala Reference Manala2015). However, as several papers in this special collection make clear (see also Table 1), assumptions about the inherent harms of these practices are commonly made with little reference to evidence, opening up much scope for ethnocentric bias (see also Lawson & Gibson, Reference Lawson, Gibson, Burger, Lee and Searin press). In cases such as child marriage (Baraka et al., Reference Baraka, Lawson, Schaffnit, Wamoyi and Urassa2022), bridewealth (Akurugu et al., Reference Akurugu, Dery and Bata2022), arranged marriage (Agey et al., Reference Agey, Crippen, Wells and Upreti2023) and polygynous marriage (Anderson & Bidner, Reference Anderson and Bidner2022; Lawson & Gibson, Reference Lawson and Gibson2018; Pesando, Reference Pesando2021), careful analyses present a more nuanced picture of the wellbeing (and fitness) implications of each practice. For example, some studies show that polygynous marriage is predictive of relatively poor health for women and their children, implicating resource competition and co-wife conflict (Omariba & Boyle, Reference Omariba and Boyle2007; Strassmann, Reference Strassmann2011), while others highlight apparent benefits for women, including greater access to male owned wealth and associated benefits of greater livelihood resilience which benefits all family members (Dessy et al., Reference Dessy, Tiberti, Tiberti and Zoundi2021; Lawson et al., Reference Lawson, James, Ngadaya, Ngowi, Mfinanga and Mulder2015).

An evidence-based and culturally sensitive approach to behaviours and practices which appear harmful can lead us away from parochial interventions that punish families making difficult decisions with limited choices. For example, Schaffnit et al. (Reference Schaffnit, Wamoyi, Urassa, Dardoumpa and Lawson2021) argue that criminalising marriage under 18 years may be damaging for adolescent girls and young women by constraining their options, unless such interventions are also effectively combined with policies addressing the vulnerabilities experienced by those delaying marriage, i.e. exposure to risky sexual behaviour, premarital childbearing and negative social judgements of unmarried women. By adding ethnographically grounded and contextually specific analyses, evolutionary social scientists have much to contribute to the difficult task of disentangling to what extent alternative cultural practices are best understood as a root cause of gender inequality or rather a product of constrained options (or both). Women, for example, may accept the apparent costs of bridewealth on their agency, because to fail to do so risks leaving their children illegitimate, but also because a potential spouse's ability to pay bridewealth is an honest signal of his ultimate ability to provide for her and her future family in contexts where women's ability to generate wealth independently is limited by wider patriarchal norms (Akurugu et al., Reference Akurugu, Dery and Bata2022).

FGMC provides a particularly interesting case where many evolutionary scientists and global health professionals share similar assumptions about the likely motivations behind the procedure, but where attempts to empirically test these assumptions have revealed mixed results. For example, via analysis of African demographic survey data, Howard and Gibson (Reference Howard and Gibson2017) present data consistent with the importance of FGMC in marriage markets; cut women achieve higher reproductive success than uncut women in areas where the practice is most common. However, in subsequent analyses they also reject the idea that the practice benefits men (from a fitness perspective) by controlling women's sexuality, reporting no association with FGCM and women's reported sexual activity (Howard & Gibson, Reference Howard and Gibson2019). Efferson et al. (Reference Efferson, Vogt, Elhadi, Ahmed and Fehr2015) also piqued the attention of global health professionals by challenging a popular notion that the maintenance of FGMC in a population depends on a critical number of families who cut their daughters and demand cut daughters-in-law for their sons (see Mackie & LeJeune, Reference Mackie and LeJeune2009). Efferson et al. (Reference Efferson, Vogt, Elhadi, Ahmed and Fehr2015) found no evidence that cutting was coordinated within a large sample of Sudanese communities, and substantial variation in attitudes and cutting behaviour between individual families. This finding implies that rather than allocating limited resources to mass abandonment ceremonies to force numbers below a tipping-point, any intervention which reduces even small numbers of cutters could contribute to a cumulative reduction in FGMC over time (for further discussion see Lawson & Gibson, Reference Lawson, Gibson, Burger, Lee and Searin press).

A second emergent theme is presented by several papers in the collection addressing how patterns of gendered conflict are being influenced by market integration (Agey et al., Reference Agey, Crippen, Wells and Upreti2023; Mattison et al., Reference Mattison, MacLaren, Sum, Mattison, Liu, Shenk and Wander2023; Schaffnit et al., Reference Schaffnit, Page, Lynch, Spake, Sear, Sosis and Shenk2023). Mattison et al. (Reference Mattison, MacLaren, Sum, Mattison, Liu, Shenk and Wander2023), for example, incorporate a consideration of matrilineal vs. patrilineal kinship to provide a fresh perspective on long-running debates about the impact of market integration on wealth inequality. They find matrilineal Mosuo in Southwestern China have greater wealth inequality than their patrilineal counterparts, which they attribute to higher levels of market integration among this group. However, within matrilineal communities, greater wealth was associated with lower inequality, highlighting the importance of sharing norms and institutions in counterbalancing inequalities that may otherwise arise. Given the absence of similar redistributive mechanisms in patrilineal groups, they speculate that wealth differences will become relatively more apparent with greater economic development.

Schaffnit et al. (Reference Schaffnit, Page, Lynch, Spake, Sear, Sosis and Shenk2023) and Agey et al. (Reference Agey, Crippen, Wells and Upreti2023) address the influence of market integration on patterns of arranged marriage, a site of both potential parent–offspring conflict and gendered conflict (as arranged marriage more often involves coercion of wives and daughters than husbands and sons). Drawing on data from Bangladesh, Schaffnit et al. (Reference Schaffnit, Page, Lynch, Spake, Sear, Sosis and Shenk2023) find that contrary to their expectations, markers of family market integration do not predict whether women enter an arranged or love marriage. They argue that while access to education and participation in the workforce has opened up more avenues for women to choose their spouse, the adoption of love marriage as an individual practice does not depend solely on socioeconomic factors. Further, they show that dowry payments and gifts continue to be made by parents even when their daughters are the ones who choose their spouse, suggesting parental approval remains an important factor. Agey et al. (Reference Agey, Crippen, Wells and Upreti2023) highlight the greater potential for disagreement over spouse choice between parents and daughters (relative to sons) in Nepal, where love marriages are on the rise among the younger generation. Parents can choose to withhold dowry payments if they disapprove of the marriage, which can strain daughters’ relationship with her new in-laws. Women who elope against their parents’ wishes may find themselves socially isolated and at greater risk of domestic abuse. In contrast, men are typically less beholden to their parents and so generally receive less scrutiny about their marital choices. These findings highlight the disparate effects of market integration for women and men, which should be considered by policymakers working in societies experiencing rapid socioeconomic transitions.

Finally, several papers address intracultural variation in gender ideology across time and space. Lawson et al. (Reference Lawson, Schaffnit, Kilgallen, Kumogola, Galura and Urassa2021b) consider women's empowerment from a conflict perspective, exploring the correlates of men's gender ideology in a semi-urban community in Mwanza, Tanzania. They find that men's support for women's empowerment is domain specific, and greatest for domains that do not entail an explicit cost to men. For instance, men were largely in favour of the education of girls and women's participation in the workforce and the community's political life, which were perceived to improve both men and women's socioeconomic standing and quality of life. However, they were far less supportive of women's authority over the household decision-making process and were more likely to agree that husbands have a right to engage in IPV. They also find little evidence that potential demographic indicators of gendered conflict (polygynous marriage, large spousal age gap, high fertility) were predictive of men's beliefs, underscoring the notion that these behaviours have more nuanced relationships with gender relations within communities than often assumed by global health professionals, or implied by crude cross-national analyses.

Kerry et al. (Reference Kerry, Blake, Murray and Brooks2021) and He et al. (Reference He, Rui, Zhang, Tao, Wu, Mace and Ji2022) also provide novel investigations into the role of kin in determining gender relations. Using data from an online survey in the United States, Kerry et al. (Reference Kerry, Blake, Murray and Brooks2021) find those who have more male than female kin hold less favourable views on gender-related political issues, suggesting political attitudes are motivated not only by one's own sex, but also the gender and reproductive opportunities of one's descendants. This may also help explain why women sometimes support policies that limit their autonomy and have the potential to be harmful to their personal wellbeing (see also Brooks & Blake, Reference Brooks and Blake2019). He et al. (Reference He, Rui, Zhang, Tao, Wu, Mace and Ji2022), on the other hand, show that, for the Mosuo of China, while living with matrilineal kin may benefit women in some regards, the more reproducing women in the household the lower the probability is that the husband will help on a wife's farm. The authors suggest that decreases in a man's help on their wife's farm are motivated by potential fitness benefits of such help being diluted by unrelated members of their wife's household. Together these studies highlight the potential for evolutionary perspectives, by uniquely modelling fitness considerations, to provide novel insights into gender relations across and within cultural contexts.