Psychological Adaptations: A Model and It's Relevance
We are accustomed to thinking of giraffes' necks or peacock displays when we consider natural selection and adaptations. Our own patterns of behavior and correlated physical structures seem less remarkable, as if any other structure would be ridiculous or impossible. We are likely unaware of our own structure, whatever it may be. It's also likely that giraffes find nothing peculiar about long necks.
Barkow et al (1992, The Adapted Mind: Evolutionary Psychology and the Generation of Culture, Oxford Univ Press, p 24) define a Psychological Adaptation (PA) as: a) An information processing system ... with sensory, central, and motor elements b) Highly efficient with specific inputs and specific outputs c) A combination of cognitive, limbic, brainstem, autonomic, hormonal, and spinal components as well as the associated muscular, skeletal, neural, and organ specializations. d) A solution to a "survival problem" that can be usefully identified and classified by the problem that is solved. PAs are likely products of natural selection.
Our psychological structure has been compared to computer systems (as if a particular type of mind builds a similar type of mind but with different materials!). We can also compare it to a mosaic of biological tiles, differing in colors but assembled while still wet and the hue allowed to bleed between adjacent blocks. "Smiling at a baby" is one subsection of the larger PA of child rearing; each of us does it a little differently depending on our histories and on other PAs that we do or do not have.
Relevance: a) PAs are presumed to generate a uniformity of behavior across human societies and are a key element in the development of culture. Examples of PA include: Language Acquisition & Use, Group Formation, Kin Recognition, Child Rearing, Mating, Food Acquisition and Sharing, Gossip, Humor, Incest Avoidance, Deception, and Social Exchange. There are subroutines. For example, Child Rearing may include Morning Sickness, preferential investment in healthier children, parental and child vocal patterns, and play fighting. It would be possible to build long, arbitrary lists of PAs; however, there is some preliminary data for each of the above being a plausible PA. b) Cognitions are one component of PAs and are tied to specific affective, autonomic, and motor systems. Thoughts of an adulterous spouse may elicit hatred and anger, changes in heart rate, pupillary dilation, and blood pressure, searching behaviors, threats, and aggression. c) Cognitions are often a specific response to highly specific stimuli. For example, we can expect highly accurate psychological responses to signals that reflect disgust, anger, fear, attraction, jealousy, lying, or disbelief. d) Cognitions are generally "content specific"; that is, our minds are specialized to make certain types of comparisons efficiently, form certain types of memories, and generate certain types of responses (See also "Mapping the Mind: Domain Specificity in Cognition & Culture" by Shelman & Hirschfeld, 1994, Cambridge Univ Press for a more advanced discussion of cognitive specificity.)
If PAs are a result of natural selection, then we can expect: a) Some variability in PAs to occur between individuals. Some women, for example, may be highly maternal, others may be the opposite. b) There to be reproductive competition between people who show differing expressions of a PA c) A PA that confers reproductive success might be expected to occur in more individuals with each generation. Thus, PAs might assume the properties of genes or memes (Dawkins R, 1989, The Selfish Gene, Oxford Univ Press). That is, their existence can be traced across generations of people, independently of any single carrier (person). They may compete with or compliment each other and their expression can vary sharply as a function of other PAs, ontogeny, environmental releasers, or cultural support. d) PAs are likely to be compatible, supportive of one another, and expressed in parallel, hierarchic, or nested combinations. d) Some incompatibility will exist between different PAs. This incompatibility can enhance survival or may encourage dysfunctional behaviors. Competing PAs can even provide a therapeutic tool if used correctly.
More to come ...