The focus of evolutionary psychology has been most clearly defined by Leda Cosmides and John Tooby, two researchers currently at UC Santa Barbara. Evolutionary psychologists (EP) are interested in studying the evolved cognitive structure of the mind. EP argue that much has changed since the mind evolved in the ancestral environment, and behaviours observed today may or may not be adaptive. The focus of study is on psychological or mental mechanisms, also referred to as decision processes, information processes, or Darwinian algorithms. Darwinian algorithms are defined as:
"Innate specialized learning mechanisms that evolved in ancestral populations for organizing experience into adaptively meaningful schemes or frames."
The mechanisms and processes described above are proximate mechanisms. Proximate or immediate causes are the immediate factors responsible for a particular response, such as internal physiology, previous experience, conditions in the environment, etc. Although the mechanisms and decision processes they study are proximate, evolutionary psychologists believe these mechanisms were shaped by natural selection. The goal of EP is to define the workings of psychological mechanisms, including the constraints on their operation and the effects and influence of various environmental inputs (from the immediate social or physical environment and/or from experience and learning).
Identifying the stresses and problems that early humans faced (those that impacted highly on their survival and reproductive success) is a necessary first step. These stresses and problems can be both physical (e.g. staying warm, keeping away from predators, getting enough food, getting proper nutrients, avoiding disease) and social (e.g. finding a mate, maintaining reciprocal relationships, avoiding cheaters or harmful individuals, acquiring status, protecting oneself from enemies, communicating with others, maintaining group cohesion). It has been argued that stresses and problems dealing with social interaction had the largest impact on the development of the human mind.
As a result of selection pressures, anatomical, physical and mental mechanisms evolved to deal with these problems. EP are concerned with the mental mechanisms that evolved. Types of psychological mechanisms that researchers in this area have explored include cheater-detection mechanisms, kin-recognition mechanisms, and mate choice mechanisms.
Some differences may have little impact, some may change the behaviours produced from the original function, other differences may lead to maladaptive behaviour and impaired psychological functioning.
Evolutionary psychologists are interested in studying psychological mechanisms that are universal, hence having little or no genetic differences among individuals. In contrast, Darwinian anthropologists have no specific requirements on the heritability of a behaviour they are studying.
Reproduction (attracting a mate, mating, gestation, raising offspring) is a very costly endeavor. As a result, natural selection must have produced adaptations which were finely tuned for analyzing the environment to ensure successful reproduction and survival of the offspring. Another reason for studying traits closely linked to reproduction is that selection pressures on these traits are very strong, causing genetic variability, and hence heritability, to decrease.
Mental mechanisms that evolved in response to social or physical problems in the ancestral environment are expected to be sensitive to informational cues that affected the functioning of those mechanisms. For example, degree of familiarity may have been a cue two which kinship mechanisms were sensitive because it likely correlated with degree of kinship.
We would also expect psychological mechanisms to be sensitive to environmental conditions because with low heritability, individual differences that arise are due to environmental differences. As a result the psychological mechanisms must be able to evaluate relevant environmental cues. Recall that scorpionfly males have mating strategies with low heritability. The mating strategy that is used is contingent upon the degree of male-male competition in the environment.
* Portions of the above text are taken from the Psychology 385 Distance Education Study Guide (1996) by Charles Crawford and Maria Janicki, ©Simon Fraser University, Burnaby, British Columbia, Canada.
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