Exploratory ventures outside the established disciplinary boundaries can yield added insights and explanatory power. Imposing cognitive limitations on human logical reasoning ability (bounded rationality) is a well-known case in point. Extending cognition to parts of body outside the brain, and to environment outside the body is another. In contrast, the present article takes a constructive approach, also in an exploratory spirit. For the sake of exposition, we consider three tiered realms of scientific inquiry: physical or inanimate, biological or animate, and socio-psychological or sentient. In this three-tier framework, we explore the extent of gains in modeling human action within the confines of physical principles such as optimization. In this exercise, concepts of complexity and emergence account for the absence of analytically derivable mapping from micro or finer grain phenomena to macro or coarser grain phenomena. A general notion of embodiment captures the inclusion of a more expansive range of explanatory factors in modeling and understanding a given phenomenon. Emergence and embodiment play complementary roles in exploration of human behavior.
We propose framing human action in physics before reaching to biology and social sciences, rearranging the order of their usual deployment. As an example, consider efforts to model altruism that start in a frame of psychological or social attributes such as reciprocity, empathy, and identity. Evolutionary roots might also be used by appeal to survival of the species from biology. Only then the modeler abstracts to work on notations, and to establish relationships using mathematical apparatus from physics. This top-down deployment of principles from various scientific disciplines has generated a body of coherent models, partially generalizable theories, and disagreements. In this paper we present a definition of action as a movement between two points in the relevant space, and explore reversing the direction of deploying scientific theories, starting with the principle of least action in physics to frame observed human action. Used as an organizing principle of the whole universe, optimization element in human behavior does not have to be presumed to arise from animate aspects of adaptive and cognitive faculties; emergence of social phenomena, when optimal, can be disconnected from methodological individualism. Our three-tier framework makes room for physical, biological and social science principles, proposing a new perspective on human behavior, sans reductionism.
Social sciences start by looking at the social-psychological attributes of humans to model and explain their observed behavior. However, we suggest starting the study of observed human behavior with the universal laws of physics, e.g., the principle of minimum action. In our proposed three-tier framework, behavior is a manifestation of action driven by physical, biological, and social-psychological principles at the core, intermediate, and top tier, respectively. More broadly, this reordering is an initial step towards building a platform for reorganizing the research methods used for theorizing and modeling behavior. This perspective outlines and illustrates how a physical law can account for observed human behavior and sketches the elements of a broader agenda.