The target article offers a novel process-oriented reconceptualization of egalitarian societies, advancing an integrative framework that links individual motivations, socio-ecological conditions, egalitarian processes, and inequality. Despite its theoretical innovation, the framework places primary emphasis on self-interested motivations and disadvantageous inequality aversion while underestimating the extent to which egalitarian behavior may be guided by multiple coexisting motivations. In particular, aversion to advantageous inequality may play an important yet underappreciated role in egalitarian processes, ultimately contributing to the maintenance of relative equality. Below, we explain why incorporating aversion to advantageous inequality would complement and strengthen the proposed framework.

Advantageous inequality aversion as a unique motivation. The target article acknowledges that disadvantageous inequality outcomes can activate both self-interested motives and disadvantageous inequality aversion. However, aversion to advantageous inequality outcomes has also been documented not only in industrialized societies (Fehr & Schmidt, Reference Fehr and Schmidt1999; Luo et al., Reference Luo, Hétu, Lohrenz, Hula, Dayan, Ramey, Sonnier-Netto, Lisinski, LaConte and Nolte2018) but also in nominally egalitarian societies – for example, among the Au and Gnau of Papua New Guinea, who reject unequal offers in the Ultimatum Game regardless of whether the offers favor or disfavor themselves (Henrich et al., Reference Henrich, Boyd, Bowles, Camerer, Fehr, Gintis, McElreath, Alvard, Barr, Ensminger, Henrich, Hill, Gil-White, Gurven, Marlowe, Patton and Tracer2005) – and even in non-human primates (e.g., chimpanzees) (Brosnan & De Waal, Reference Brosnan and De Waal2014). Converging neuroscientific evidence from fMRI studies further shows that advantageous inequality elicits brain activation profiles distinct from those associated with disadvantageous inequality, supporting their motivational distinctiveness (Bellucci et al., Reference Bellucci, Feng, Camilleri, Eickhoff and Krueger2018; Gao et al., Reference Gao, Yu, Sáez, Blue, Zhu, Hsu and Zhou2018; Li et al., Reference Li, Lai, Li, Madsen, Xiao, Hu, Feng, Fu and Liu2024). Taken together, these findings suggest that aversion to advantageous inequality represents a missing yet independent motivational component in the framework proposed by the target article.

Advantageous inequality aversion guides egalitarian processes. Many egalitarian processes highlighted in the target article, including demand-sharing, risk-pooling, prosocial reputation-building, and status-levelling, often manifest as altruistic behaviors involving either direct resource provision or third-party intervention in unequal resource allocation. Extensive research in behavioral economics and social psychology suggests that, beyond self-interest and disadvantageous inequality aversion, advantageous inequality aversion makes a non-redundant contribution to explaining altruistic behaviors in resource distribution contexts, which are central to egalitarian processes (e.g., Fehr & Schmidt, Reference Fehr and Schmidt1999; Gao et al., Reference Gao, Yu, Sáez, Blue, Zhu, Hsu and Zhou2018; Wu et al., Reference Wu, Ren, Liu and Zhang2024). Thus, aversion to advantageous inequality constitutes a non-negligible motivation underlying egalitarian processes.

Disentangling advantageous inequality aversion from self-interested reputation seeking. Altruistic behaviors central to egalitarian processes could be motivated by advantageous inequality aversion. However, as the target article also notes, an alternative explanation is that such behaviors reflect self-interested concerns, particularly the pursuit of reputation and social status through prosocial displays. Supporting the first view, prior studies show that even in anonymous contexts where reputational incentives are minimal, individuals remain willing to allocate resources to others (Eckel & Grossman, Reference Eckel and Grossman1996; Umer, Reference Umer2023). Supporting the second view, substantial evidence indicates that individuals behave more fairly and altruistically when reputational benefits can be obtained (e.g., Andreoni & Bernheim, Reference Andreoni and Bernheim2009; Li et al., Reference Li, Hu, Xu and Li2021; Qu et al., Reference Qu, Météreau, Butera, Villeval and Dreher2019). These findings, largely derived from participants in industrialized societies, suggest that advantageous inequality aversion and self-interested reputation-seeking motivations may coexist within egalitarian processes. Future research would benefit from experimentally manipulating anonymity versus identifiability (e.g., Feng, Tian, & Luo, Reference Feng, Tian and Luo2023) and combining such designs with computational modeling approaches to disentangle these motivations across a broad range of social contexts and populations, from nominally egalitarian societies to industrialized societies.

Contexts in which self-interest cannot explain egalitarian processes. When individuals accidentally inflict physical or economic harm on others, an inequality arises between the perpetrator and the victim (Urbanska, McKeown, & Taylor, Reference Urbanska, McKeown and Taylor2019). Providing compensation in such contexts serves to restore this disrupted equality and can thus be understood as an egalitarian process (e.g., status-levelling). In a recent study, we modeled individuals’ compensatory decisions and found that, compared with models incorporating self-interest, models excluding self-interested motivations provided a better account of compensatory behavior (Zhu et al., Reference Zhu, Wang, Feng, Yin, Zhang and Liu2025). These findings suggest that, when determining how much to compensate, individuals primarily focus on delivering an appropriate level of restitution to the victim while largely disregarding considerations of self-interest. Accordingly, a theoretical framework that includes only self-interested motivations has difficulty accounting for such egalitarian behavior. Incorporating additional motivational components – such as aversion to advantageous inequality – is therefore necessary to enhance the framework’s explanatory power. In compensatory contexts, for example, perpetrators’ actions can be understood as motivated by a desire to reduce the advantageous inequality created by their harmful behavior.

Relying solely on self-interested motivations has difficulty explaining a broad range of altruistic behaviors central to egalitarian processes (e.g., Henrich et al., Reference Henrich, Boyd, Bowles, Camerer, Fehr, Gintis, McElreath, Alvard, Barr, Ensminger, Henrich, Hill, Gil-White, Gurven, Marlowe, Patton and Tracer2005). Motivations underlying egalitarian processes are therefore likely to be plural and complex (e.g., Li et al., Reference Li, Hu, Ruff and Zhou2022; Wu et al., Reference Wu, Ren, Liu and Zhang2024). By demonstrating the unique explanatory power of aversion to advantageous inequality and highlighting contexts in which self-interested motivations are insufficient, we suggest that explicitly incorporating aversion to advantageous inequality as an additional motivational component would strengthen the theoretical completeness of the target article’s framework.