Divestiture of Psychology

There is growing unease about progressive divestiture of different aspects of psychology to biology. Each week the popular press reports discovery of a new genetic determinant of human behavior, with remedial pills not far behind. It is feared that as we give away more and more psychology to disciplines lower down on the food chain, there will be no core psychological discipline left. Foreclosure is our destiny.

This line of thinking is unmitigated reductionism. With the dignified burial of the dualistic Decartes, it is now acknowledged that psychological processes are brain activities, not immaterial entities. But physicality does not imply reduction of psychology to biology.

Knowing how the biological machinery works tells one little about how to orchestrate that machinery for diverse purposes. To use an analogy, knowing how a television set produces images in no way explains the nature of the creative programs it transmits. To switch the analogical machinery, the software is not reducible to the hardware. Each is governed by its own set of principles that must be studied in its own right.

Much of psychology is concerned with discovering principles about how to structure psychosocial factors to achieve desired outcomes. This subject matter does not have a counterpart in neurobiological theory and, therefore, psychological laws are not derivable from it. For example, knowledge of the brain circuitry involved in learning does not tell one much about how best to devise conditions of learning in terms of levels of abstractness, novelty, and challenge; how to provide incentives to get people to attend to, process, and organize relevant information; in what modes to present information; and whether learning is better achieved independently, cooperatively, or competitively. The optimal conditions must be specified by psychological principles. Nor does understanding how the brain works furnish rules on how to create efficacious parents, teachers, or executives.

Psychological principles cannot violate the neurophysiological capabilities of the systems that subserve them. But the psychological principles need to be pursued in their own right. Were one to embark on the slippery slope of reductionism, the journey would take one through biology and chemistry and eventually end in atomic subparticles. Because of emergent properties across levels of complexity, neither the intermediate locales nor the final stop in atomic subparticles supply the psychological laws of human behavior.

One-Sided Evolutionism

The biologizing of psychology is also being promoted by uncritical adoption of one-sided evolutionism. All too often, the multicausality of human behavior is misleadingly framed in terms of partitioning behavioral variance into percents nature and percents nurture. This causal dualism is mistaken for several reasons. It disregards the interdependence of nature and nurture - socially constructed nurture has a hand in shaping nature. Dualism fails to address fundamental issues concerning the operational aspect of human nature.

Social cognitive theory acknowledges the influential role of evolutionary factors in human adaptation and change. But it rejects one-sided evolutionism, in which social behavior is the product of evolved biology, but social and technological innovations that create new environmental selection pressures for adaptiveness have no effect on biological evolution.

In the bidirectional view, evolutionary pressures fostered changes in biological structures for the use of tools, which enabled an organism to manipulate, alter, and construct new environmental conditions. Environmental innovations of increasing complexity, in turn, created new selection pressure for the evolution of specialized biological systems for functional consciousness, thought, language, and symbolic communication.

Human evolution provides bodily structures and biological potentialities, not behavioral dictates. Having evolved, the advanced biological capacities can be used to created diverse cultures - aggressive, pacific, egalitarian, or autocratic ones.

As Steven J. Gould notes, biology sets constraints that vary in nature and degree. But in most domains of human functioning, biology permits a broad range of cultural possibilities. He argues cogently that evidence favors a potentialist over a determinist view of nature. In this insightful analysis, the major explanatory battle is not about nature versus nurture, but whether nature operates as a determinist or a potentialist.

Gould makes the further interesting point that biological determinism is often clothed in the language of interactionism. The bidirectional biology-culture coevolution is acknowledged, but then the major causation of human behavior is ascribed to evolved biology. Biological determinism is also often clothed in the language of changeability. The malleability of evolved proclivities is acknowledged, but determinative potency is then ascribed to them, with warnings that efforts to change existing sociostructural arrangements and practices can be harmful because they are ruled by evolved dispositions.

Cultural Diversity and Change

Theories that heavily attribute human social behavior to the rule of nature are disputed by the remarkable diversity of culture. A biologically deterministic view has problems not only with cultural diversity, but with the rapid pace of social change as well. The process of biological selection moves at a snail's pace, whereas societies have been undergoing major changes in sexual mores, family structures, social and occupational roles, and institutional practices.

Ancestral origin and the determinants governing contemporary social practices are quite different matters. Because evolved potentialities can serve diverse purposes, ancestral origin does not dictate current function, or a singular sociostructural arrangement. Social systems and practices are being changed by social means rather than by reliance on the slow protracted process of biological selection. Dobzhanky reminds us that the human species has been selected for learning capabilities and plasticity of behavior, adaptive to diverse habitats and socially constructed environments, not for behavioral fixedness. The pace of social change gives testimony that biology indeed permits a range of possibilities.

• A biological determinist view highlights inherent constraints and limitations.
• A biological potentialist view of human nature emphasizes multiform human possibilities.

Emerging Primacy of Social Forces in Coevolution

There is another important reason why psychology should be a prime player in the evolutionary process. Growth of knowledge has greatly enhanced human power to control, transform, and create environments of increasing complexity. People are not only responding to selection pressures, they are creating them with remarkable speed. We build physical technologies that drastically alter how we live our daily lives. We create mechanical devices that compensate immeasurably for our sensory and physical limitations. We develop medical and psychological methods that enable us to exert some measure of control over our physical and psychosocial lives. We have developed biological technologies to change the genetic makeup of plants and animals. We are now even cloning clones. And we are exploring methods that could alter the genetic code of humans.

People have changed little genetically over the last decades, but they have changed markedly through rapid cultural and technological evolutions in their thinking, styles of behavior, and the roles they perform. Given this variability, genetic coding that characterizes humans underscores the power of the environment orchestrated through agentic action. As people devise even more powerful technologies that transform environments, the psychosocial side of coevolution is gaining ascendancy. By creating ever-more complex environments, humans have become major agents of their own evolution, for better or for worse.