Compare Two Different Methods That Have Been Used by Evolutionary Psychologists

Compare two different methods that have been used by evolutionary psychologists.

Evolutionary psychology in seeking to increase understanding of contemporary behaviour and abilities looks not to the causal explanations of the immediate cause, but to the far reaching functional explanation of assumed evolutionary cause - then asks how and why we are as we are. These ideas are informed by many disciplines from anthropology to ethology and archaeology, what follows is a comparison of 2 methods illustrated by examples and different research methods.

One method - Observation, classification and induction bases itself on those of natural history. Observations are made within the real world, classifications are made of the numerous instances that have been seen and from here rational inferences and general laws are formulated.

Darwin used this approach in his study of the variety of Galapagos Finch in the 1830's*. Thus over a period of 4 weeks he was able to observe and record 26 different species of bird on the archipelago, further study of these led him to note the variety of shared characteristics in the birds separated only by graduation. From this he was able to classify the land birds he had observed into those that were predominantly insect eaters and those that were predominantly insect eaters.

This led him to make rational assumptions and formulate general laws about the birds' evolution. His induction being that these differences were firstly due to chance variations in inherited characteristics amongst the birds. After this, particular characteristics that gave birds a higher chance of survival in a particular environment became features (that by virtue of selection) survived and became dominant in that specific bird.

This methodology also included making deductions and so from seeing relatively stable animal populations despite high birth rates, Darwin concluded that this had to be due to high death rates, and then (amongst others such as Wallace) was able to go on to create bigger theories about selection - natural and sexual.

Another method used is Hypothetico-deductive reasoning and testing whereby on the basis of evolutionary principles that are understood and accepted, particular hypotheses or predictions are made and then tested. Kettlewell (1971)* used this method in his study of Peppered Moths. Noticing a higher occurrence of dark-coloured moths in industrial as opposed to rural areas - their higher survival was put down to the dark as oppose to light colourings giving better camouflage against the soot coated trees and walls of the environment. Thus a prediction that an environmental change to one of less soot (lighter) would result in higher instances of light moth industrial areas could be made.

Kettlewell was able to test and demonstrate this in a follow up study when the environmental conditions had become less polluted. This was not to say that the moths deliberately changed colour in accordance with the environmental changes but that as more survived and were able have a long enough life span to produce off spring their numbers increased until they dominated.

This method has also been used to hypothesise about the development of cognitive structures for intelligence as a means of adapting to the problems early humans faced as hunter gathering social beings. Byrne and Whiten (1988)*, inspired by the Humphrey (1976)* paper entitled 'The social function of intellect' put forward their Machiavellian hypothesis arguing this was because of the benefits to social creatures (like hunter gathers from who we descend) of mastering the complex balancing act of competition and co-operation such that they could determine what the results of their actions might be, what the actions of another might be whilst weighting up what would be