Evolutionary Psychology

1 Evolutionary Psychology

. Introduction

How do we explain, predict and control human behavior? This question remains a central underlying theme within psychology as a whole. Few specific branches of psychology have attempted to integrate multiple perspectives within their fields of research. Evolutionary psychology appears to be unique in this endeavor, and as the following researchers point out, "Evolutionary psychology is the long-forestalled scientific attempt to assemble out of the disjointed, fragmentary, and mutually contradictory human disciplines a single, logically integrated research framework for the psychological, social, and behavioural sciences--a framework that not only incorporates the evolutionary sciences on a full and equal basis, but that systematically works out all of the revisions in existing belief and research practice that such a synthesis requires" (Tooby &ump; Cosmides, 2005)

A unification of this type is unquestionably an enormous undertaking, but as the following review ventures, it is likely to be a worthwhile contribution to a number of existing disciplines.

2. Goals and Theoretical Framework

In order to reach any type of conclusion with regard to how much of human behaviour can be explained by an evolutionary psychology framework, it is necessary to understand what the goals of such a subject area are: "The goal of evolutionary psychology is to study human behaviour as the product of evolved psychological mechanisms that depend on internal and environmental input for their development, activation, and expression in manifest behaviour." (Buss, et al., 2010)

Like physiology, anatomy and biology, evolutionary psychology examines human behaviour from a Darwinian perspective. That is, like physical traits, psychological traits can be transmitted genetically from parent to offspring. As Darwin proposed, those adaptations and variants that contributed most beneficially to both survival and reproduction of an organism within a given environment would occur in greater frequency in following generations than those that did not, thus resulting in species-typical characteristics (Rossano 2003).

As put forth by researchers Tooby and Cosmides (2005), natural selection of psychological processes occurs through three outcomes: 1) Adaptations, as demonstrated in traits which function to consistently solve specific adaptive problems of survival and reproduction, 2) Byproducts: or those non-functional characteristics which endure as a result of coupling with existing adaptations, and finally 3) Noise, consisting of variability within a particular characteristic which may be the result of a genetic mutation or other random environmental factors.

With this in mind, it appears that evolutionary psychology endeavours to explain the vast majority of human behaviour. However, that is not to say that it is without its limitations in that respect. In the following analysis, I will attempt and overview of some generally established behaviours seen across both human and non-human animals that can explained by evolutionary psychology as having adaptive value, by-product characteristics and noise while also addressing some aspects of human behaviour that evolutionary psychology has difficulty explaining under the current theoretical framework.

3. Adaptations for Survival and Reproduction

One of the main criticisms levelled at evolutionary psychologists is that knowledge of human history is limited, and unknowable. As Tooby and Cosmides (2005) state, "we can know nothing about the past that is relevant to psychology because behaviour doesn't fossilize". This, as the researchers counter, is categorically false. In knowing basic principles of the environment of evolutionary adaptedness, such as a world governed by principles of physics, and through knowledge of necessities for reproductive success (eg., that successful sexual reproduction requires two separate and distinct sexes to occur), behaviour research from an evolutionary psychological point of view certainly has a reasonable and plausible foundation. As pointed out by Tooby and Comsides (2005), knowledge of ancestral hominids abounds. It is known that hominids were sexually dimorphic, omnivorous hunter-gatherers, producing altricial young. They also lived in small cooperative, nomadic, kin-based groups of individuals. Even from this basic information, evolutionary psychologists are able to cultivate and enhance theories of behaviour within these environments.

For instance, an established emotion seen in both human and non-human animals such as fear provides an example of evidence that evolutionary psychology can explain not only the emotion itself, but also those by-product and noise emotions connected to fear that may not be immediately identified as the result of natural selection. Mineka and Ohman (2003) propose a fear module based on research into fear conditioning in humans of snakes and spiders. They found that humans were conditioned much quicker to fear snakes and spiders than other stimuli that would have been in an evolutionary sense, non-threatening. This suggests a certain type of pre-existing adaptive module for fear and survival. In an evolutionary environment, snakes and spiders presented a very real threat to hominids, and to be able to fear these organisms without previous knowledge of their lethal capabilities would be highly adaptive.

In turn, through examination of this single emotion, fear by-products or noise can also be accounted for. For example, those individuals who might acquire a fear of non-poisonous snakes demonstrate an adaptive by-product of fear and individuals who acquire maladaptive fears, or phobias in which they are somehow hindered by otherwise unusual or generally non-threatening stimuli can be said to