The target article’s 2-tiered model proposes that energetic resources (Tier 1) and environmental mortality cues (Tier 2) shape life history strategies. The article provides convincing data rebuking a 1-tiered model focused purely on energetic constraints. However, environmental factors do not directly drive life history outcomes, but rather interact with psychological processes to drive behavior.

In Tier 2 of the proposed model, life history outcomes are strongly mediated by cognitive and affective processes, including whether mortality cues are attended, how mortality is conceptually framed, and which motivational states are evoked in response. In Tier 1 of the model, psychological processes even mediate the relationship between external bioenergetic resources and the timing of sexual development (see Figure 1). Below, we review several psychological processes, which help to explain important interindividual variance in life history outcomes that the present model cannot account for.

Figure 1.

Cognitive and affective processes mediate the effects of environmental factors on life history outcomes.

Attention: Perceived environmental danger does not always match actual environmental danger, because it is determined by which sensory cues we attend to. Although certain threat cues (e.g., loud noises) capture attention in the vast majority of individuals, attention is also drawn to stimuli that align with an individual’s particular goals and attentional selection history, while stimuli that do not align may be missed (Kim et al, Reference Kim, Lee, Grindell and Anderson2024; Mack & Rock, Reference Mack and Rock1998). The detection of visual threat cues is thus idiosyncratic, with different individuals “seeing the world as they are” – such that, e.g., those with chronic pain attend more to visual cues to pain, and anxious individuals attend more to visual cues to danger (Lewis et al., Reference Lewis, Blanco, Raila and Joormann2019; Mahmoodi-Aghdam et al, Reference Mahmoodi-Aghdam, Dehghani, Ahmadi, Khorrami Banaraki and Khatibi2017; Neff & Buck, Reference Neff and Buck2022; Raila, Scholl, Gruber, Reference Raila, Scholl and Gruber2015). Accordingly, differences in visual attention may help to explain why anxious individuals have faster life history strategies (Hurst & Kavanagh, Reference Hurst and Kavanagh2017).

Cognitive biases: Even after an individual perceives cues to environmental mortality, reasoning biases such as “framing effects” can influence how they assess risk. For example, people tend to more strongly overestimate the risks of their plane crashing on the day of their flight (when more details about it are cognitively available), compared to a week before (Lermer et al., Reference Lermer, Streicher, Sachs, Raue and Frey2016; Trope & Liberman, Reference Trope and Liberman2003). Perhaps most pernicious is confirmation bias: people seek out information that confirms their beliefs and discount contradictory evidence (Mynatt, Doherty, & Tweney, Reference Mynatt, Doherty and Tweney1977; Oktar & Lombrozo, Reference Oktar and Lombrozo2025; Wason, Reference Wason1960). So, someone who believes the world is a dangerous place will be difficult to convince otherwise. This may help to explain why conceptions of environmental mortality often depart from actual environmental mortality (e.g., many US citizens believe that the crime rate is increasing, when it is actually declining; Owens & Pinto, Reference Owens and Pinto2021).

Social learning: Another explanation for disconnects between perceived and actual mortality is that much of the information that people receive about environmental threats is not received firsthand, but rather through social observation. For example, some individuals may learn to fear relatively harmless animals, such as frogs and bats, due to misinformation which they have received from others (Zeller et al., Reference Zeller, Mouquet, Garcia, Dezecache, Maille, Duboscq, Morino and Bonnet2025). Social learning has long played a fundamental role in human development (Sterelny, Reference Sterelny2012) and has also been observed in many nonhuman species. For example, one might expect rhesus monkeys to innately fear snakes – but in fact they learn to fear them after seeing a conspecific react fearfully (Mineka et al., Reference Mineka, Davidson, Cook and Keir1984). In humans, the social transmission of (mis)information serves many purposes (e.g., facilitating social coordination) – and so relying on information from others may not always result in veridical perception of environmental threats (Hilton & Liu, Reference Hilton and Liu2008; Hirst & Coman, Reference Hirst and Coman2018).

Motivation: Even when one’s perception of environmental mortality is accurate, different motivations can arise in response, and different life history outcomes may occur as a result. Mortality cues can cause a motivation to capitalize on presently available opportunities, due to uncertainty about whether such opportunities will be available into the future (Leyva et al., Reference Leyva, Mengelkoch, Gassen, Ellis, Russell and Hill2020). However, mortality cues can also produce a motivation to “live on” by leaving a legacy or “mark” on the world (Becker, Reference Becker1973). And while people can satisfy this motivation by having children, this drive can also be satisfied with other actions, such as making intellectual or artistic contributions (Fritsche et al., Reference Fritsche, Jonas, Fischer, Koranyi, Berger and Fleischmann2007; Perach & Wisman, Reference Perach and Wisman2019; Solomon, Greenberg, & Pyszczynski, Reference Solomon, Greenberg and Pyszczynski1991). Persisting connections with others and a secure attachment style can also buffer one against death anxiety, enabling slower life history outcomes to emerge despite the presence of environmental mortality cues (Hirschberger, Florian, & Mikulincer, Reference Hirschberger, Florian and Mikulincer2002; Mikulincer & Florian, Reference Mikulincer and Florian2000; Taubman-Ben-Ari, Findler, & Mikulincer, Reference Taubman-Ben-Ari, Findler and Mikulincer2002). Even emotional connections to pets strongly mediate reproductive behaviors – with many couples choosing to care for “fur babies” in place of children (Kubinyi, Reference Kubinyi2025). In order to predict the effects that environmental mortality cues have on life history outcomes, it is necessary to consider which particular motivations they evoke and which actions are available to satisfy those motivations.

Psychological processes even mediate the relationship between external bioenergetic resources and the timing of sexual development in Tier 1. For example, body image distortions, insecure attachment styles, and internalization of cultural body ideals can trigger behaviors like food restriction, leading to delays in sexual development even in the absence of food scarcity (Easter, Treasure, & Micali, Reference Easter, Treasure and Micali2011; Hoffman, Zerwas, & Bulik, Reference Hoffman, Zerwas and Bulik2011; Puckett et al., Reference Puckett, Grayeb, Khatri, Cass and Mehler2021). Anorexia nervosa, which has the highest mortality rate of any psychiatric disorder and which occurs across all levels of socioeconomic status, serves as an extreme case of such mediation (Auger et al., Reference Auger, Potter, Ukah, Low, Israël, Steiger, Healy-Profitós and Paradis2021; Huryk, Drury, & Loeb, Reference Huryk, Drury and Loeb2021).

The target article provides data that successfully refute a 1-tiered model: there seems to be evidence for an accelerated life history strategy in response to environmental mortality cues, after accounting for the most severe bioenergetic limits. However, most of the variance in life history strategy will be unaccounted for without diving into human psychology.