Ko and Neuberg’s overarching premise is that the human lifespan can be broken down into categorical variables that emphasize different ecological affordances for maximizing development during three major life stages: childhood, mating, and parenting. Specifically, Ko and Neuberg define ecological affordance as “the opportunities and threats an environment poses for achieving one’s goals” according to different developmental stages, and contend that “little is known, however, about how human-environment interactions vary across the lifespan.” While it may be true that developmental psychologists know little about variations in human-environment interactions, it is only because they have overlooked an entire field of study known as behavior analysis, which regards the study of behavior-environment relations for humans and non-human organisms as a natural science.

Behavior analysis stems from the study of environmental relations. Early work in the field examined stimulus pairing, such as shifting the control over a reflex from an unconditioned stimulus (e.g., food) to a conditioned stimulus (e.g., bell). Building on the foundations of respondent conditioning, behavior analysis has been used to examine more complex behavior-environment interactions. Skinner (Reference Skinner1938) coined the term “operant” to describe how behavior operates on the environment. Behavior is not merely reflexive in the sense of post hoc, ergo propter hoc, but is selected and maintained by its consequences.

To the behaviorist, human behavior is always maintained by its reinforcing contingencies. From a proximal examination, these contingencies are constantly in flux with regard to the changing environment. From an ultimate perspective, they remain constant with regard to evolutionary selection pressures that optimize health, resources, relationships, and reproduction (Baum, Reference Baum2017). An advantage of this multiscale framework is that, instead of attempting to fragment ecological affordances into distinct categorical units – referred to here as “life stages” – behaviorism affords an analysis of the entire lifespan as a continuous variable.

By describing goal setting as a function of various life stages, Ko and Neuberg stumble into the classic circular reasoning that precludes an experimental analysis to support their theory. An initial red flag is the sheer number of theories – seven, to be precise – required to help describe the origin of these life-stage goals. One construct is dependent on another, which can be explained with the help of yet additional constructs that only move us further away from human-environment interactions. The notion of developmental stages has been shown to present nothing more than a logical fallacy: Why is the subject engaged in mating rituals? Because they have reached the mating stage of development. How do you know they have reached the mating stage of development? Because they are engaged in mating rituals. Such tautological reasoning is a textbook definition of an explanatory fiction that derails an experimental approach to understanding the human-environment interactions involved in mating and other life stages. As MacCorquodale and Meehl (Reference MacCorquodale and Meehl1948) explain, “‘Fictions’ and ‘hypothetical entities’ are sometimes introduced into a discussion of theory with a degree of trepidation and apology quite unlike the freedom with which physicists talk about atoms, mesons, fields, and the like” (p. 95). A more parsimonious approach would have been to examine the hundreds of ways human behavior can be explained, predicted, and influenced by the environment (Heward et al., Reference Heward, Critchfield, Reed, Detrich and Kimball2022).

Behaviorism is not inherently at odds with affordance theory, which is grounded in perceptual experience and frequently presented in contrast to behaviorism’s scientific methods (cf. von Uexküll, Reference von Uexküll2013). Yet behaviorists do take issue with the innate dualism of organismic variables like goal setting, described herein as an a priori hypothetical construct that motivates an individual to act. As described by Ko and Neuberg, “life stage” appears to be synonymous with “intent,” as a means for explaining why individuals or groups of people behave the way they do. But try as they might, developmental psychologists are unable to fully account for motivation by looking exclusively inside the individual. Instead of a “life stage”, behaviorists argue that motivating operations are a function of the environment. Yes, the environment affords, but it also selects!

Selectionism is the paradigm upon which a science of human behavior exists. An understanding of the complexities of human behavior is afforded through experimentation on parameters such as reinforcement schedules, delay discounting, generalization gradients, response resurgence, and derived stimulus relations, to name a few. Just as species and genes are selected to fill ecological niches throughout phylogeny, behavior is selected to achieve homeostasis despite changing environmental conditions throughout ontogeny. Consider the example provided by Ko and Neuberg in which a chair serves as both a product of respite and rescue. Sitting in a chair is selected among the available alternatives when the environmental conditions dictate such behavior (e.g., rest). Changes to the environment, such as an intruder entering the room, may then select other behavior, such as using a chair for self-defense. In both cases, the motivating operations are dictated by the particulars of the environmental context – rather than the person and their particular life stage – and the current behavior is extrapolated from the individual’s ontogenic history of reinforcement. Claiming a shift in life-stage development does nothing to help us account for the novel use of the chair as a mechanism of self-defense. It is the outcome of the behavior that determines how the chair will be used in similar situations in the future.

Goal setting becomes superfluous when all the variables that control behavior are attributed to the environment, of which the individual is a part. Behavior is selected and maintained by its consequences, whether or not the individual plans for it in advance (Skinner, Reference Skinner1984). What the environment affords are the contingencies of reinforcement that shape an individual’s behavior throughout their lifetime.