We commend Ko and Neuberg on a broad, integrative perspective of affordance-management across the lifespan. We contend that their framework gains predictive power when we add complementary theories. For example, Kenrick et al. (Reference Kenrick, Griskevicius, Neuberg and Schaller2010) clarify which needs are prioritized (e.g., immediate physiological needs over status/esteem), influencing how affordances are perceived. Similarly, Boon-Falleur, Baumard, and André (Reference Boon-Falleur, Baumard and André2025) show how resource availability and urgency alter the marginal benefits of needs, resulting in different perceived affordances.

Because humans are an obligatory social species, many affordances are provided by other people within local ecologies (e.g., care, protection, resources, coalitional support, information, mates, and modeling of skills). Navigating these environments requires selecting partners who provide commodities that best match one’s needs at each life stage. This logic aligns with biological market theory, where market-like forces shape social exchange and partner choice, with organisms tailoring their strategies to the shifting supply and demand of potential partners and commodities (Barclay, Reference Barclay2013; Noë & Hammerstein, Reference Noë and Hammerstein1994, Reference Noë and Hammerstein1995). Framed this way, the same objective ecology affords different options to different people at different times, depending on who is available, what they want, and what they can credibly offer at a given life stage.

Using a biological markets perspective, we outline the following process: environmental variation shapes perceived affordances, which aggregate into population-level market dynamics (prices, norms); then markets, in turn, remake local ecologies, and shape behavioral strategies across life-stages at the individual-level. That is:

1. 1. Environmental variation shapes affordances. As Ko and Neuberg emphasize, environments vary on many dimensions (e.g., kin prevalence, population size, density, age–sex structure, safety, and norms). This variation changes the perceived opportunities and threats within local environments at each life stage, relative to the individual’s goals, determining the relevant affordances.

2. 2. Affordances shift market dynamics (population-level). Ecological variation has at least two effects. First, it influences which traits individuals seek from partners (see above), thereby altering population norms and “prices” in the market. Second, it changes the market structure itself. For example, large populations mean a bigger market, more competition over partners, and therefore more advertising of one’s traits (e.g., Barclay, Reference Barclay2011); sex ratio shifts the balance of supply and demand between men and women, while demographic structure shifts the balance of needs and contributions across ages. Some ecologies affect the degree of partner choice itself, e.g., people are freer to switch social partners in environments with fewer external threats like scarcity, conflict, and disease (Gelfand et al., Reference Gelfand, Raver, Nishii, Leslie, Lun, Lim and Yamaguchi2011; Harrington & Gelfand, Reference Harrington and Gelfand2014) or with a history of wheat instead of rice farming (Thomson et al., Reference Thomson, Yuki, Talhelm, Schug, Kito, Ayanian and Visserman2018). Thus, ecology affects not only the desirability and availability of different traits but also people’s ability to obtain them.

3. 3. Biological markets create ecological feedback. This relationship is bidirectional, where market dynamics affect ecology. Both switching costs (e.g., relational mobility) and strategy selection affect who associates with whom, and the local social rules – altering kin prevalence, density, sex ratio, safety, and norms within environments. Consequences vary according to an individual’s life stage; for example, the migration of young adults for university creates denser mating markets in university cities (vs. thinner markets in home towns); women’s rights lowers the cost of switching partners, impacting marriage norms and family structures. These moves create environmental changes – shifting the affordance landscape for the next generation (e.g., ecological approach to cultural accumulation; Baumard & André, Reference Baumard and André2025). These population-level shifts alter the market “prices,” setting new conditions for individuals across life stages, who then calibrate their behavioral strategies.

4. 4. Market dynamics calibrate individual strategies (actor-level). Given those shifted “prices,” individuals calibrate their goals and strategies by (a) tracking market dynamics (how many viable partners/allies), (b) tracking their own relative “value” or desirability within the environment, (c) navigating switching costs (exit/entry barriers), and (d) investing to raise their relative market value (developing and advertising their traits). Which strategies are used depends on life stage, sex, status, network position, and mate/ally value – and the individual’s goals. For example, in dense, high-observability markets, adolescents may up-regulate reputation signals and assort more strongly; in sparse markets with high exit costs, parents may prioritize retention (e.g., deepening kin ties, relocating toward alloparents); in male-biased university cohorts, women become more choosy while men allocate more resources on attracting partners (Griskevicius et al., Reference Griskevicius, Tybur, Ackerman, Delton, Robertson and White2012). Indeed, biological-market work shows that partner choice amplifies cooperation and selectivity in these conditions (Barclay, Reference Barclay2013, Reference Barclay2016).