Evolutionary Psychology: A Critical Introduction: 12 (BPS Textbooks in Psychology) - Softcover

Softcover

ISBN 10: 1405191228 ISBN 13: 9781405191227

Publisher: BPS Blackwell, 2011

Synopsis

The last decade has witnessed an exciting change in our understanding of the way in which the mind operates and the reasons behind a myriad of human behaviours. The traditional idea that nurture trumps nature in explanations of human behaviour has been supplanted by the evolutionary argument that human beings share evolved mental architectures that govern their behaviour.

This volume is an introduction to evolutionary approaches to psychology, bringing together seminal work in the field and exploring the ways in which evolutionary psychological research can illuminate our understanding of human behaviours and nature. Together, the chapters in this volume present a fresh perspective on evolutionary approaches to psychology, critically evaluating the extant literature while maintaining the need for evolutionary psychologies.

About this title

About the Author

Viren Swami trained as an evolutionary psychologist, and for his doctorate examined the roles that body shape and weight play in judgements of physical attractiveness across cultures. Viren’s current research in the area focuses on the influence of evolution, culture, and individual psychology on perceptions of human beauty, and his work has been widely discussed in national and international media. Viren is also currently conducting research in other fields of interpersonal attraction, including identifying predictors of positive body image, the effect of romantic love on partner perceptions, weight-based discrimination, and the history of beauty in art and sculpture. Other current projects include research on sociocultural adjustment among sojourners, and cross-cultural differences in lay beliefs about various topics, including intelligence, conspiracy theories, mental illness, and extraterrestrial life.

From the Back Cover

The last decade has witnessed an exciting change in our understanding of the way in which the mind operates the reasons behind a myriad of human behaviours. The traditional idea that nurture trumps nature in explanations of human behaviour has been supplanted by Evolutionary Psychologists, who argue that human beings share evolved mental architectures that govern their behaviour. Indeed, Evolutionary Psychological explanations have been postulated for all manner of human behaviour, from mate choice preferences to jealousy, cheater detection to suicide bombing. Yet, not all research groups are in agreement with this perspective: some authors have challenged the Evolutionary Psychological focus on biological or genetic explanations of behaviour, while others suggest that the Evolutionary Psychological paradigm is methodologically flawed. To be sure, it is now possible to find critiques of Evolutionary Psychology from different viewpoints, and a common theme shared by such critiques is that an evolutionary approach to psychology is welcome but not sufficient. This volume, which will serve as an introduction to evolutionary approaches to psychology, will bring together seminal work in the field and explore the ways in which evolutionary psychological research can illuminate our understanding of human behaviours and nature. Together, the chapters in this volume will present a fresh perspective on evolutionary approaches to psychology, critically evaluating the extant literature while maintaining the need for evolutionary psychologies.

Most introductions to evolutionary approaches to psychology tend to take an uncritical stand, stemming from what has been dubbed ‘Evolutionary Psychological’ viewpoints. The current volume begins from the same vantage point – that an evolutionary psychology is required – but nevertheless critically examines the extant literature from different evolutionary perspectives (e.g., developmental systems sciences, evolutionary biology, evolutionary developmental psychology, cultural studies, etc). The list of potential authors (see attached document) has been compiled to reflect this critical approach.

Most introductions to evolutionary approaches to psychology tend to take an uncritical stand, stemming from what has been dubbed ‘Evolutionary Psychological’ viewpoints. The current volume begins from the same vantage point – that an evolutionary psychology is required – but nevertheless critically examines the extant literature from different evolutionary perspectives (e.g., developmental systems sciences, evolutionary biology, evolutionary developmental psychology, cultural studies, etc). The list of potential authors (see attached document) has been compiled to reflect this critical approach.

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Evolutionary Psychology

A Critical IntroductionBy Viren Swami

John Wiley & Sons

Copyright © 2010 John Wiley & Sons, Ltd
All right reserved.
ISBN: 978-1-4051-9122-7

Chapter One

Evolutionary approaches to behaviour

THOMAS E. DICKINS

CHAPTER OUTLINE

A BRIEF INTRODUCTION TO EVOLUTIONARY THEORY 5 Plasticity and evolution 12

FITNESS, SOCIOBIOLOGY AND LIFE HISTORY THEORY 16

EVOLUTIONARY PSYCHOLOGY 21

CONCLUSION 25

ACKNOWLEDGEMENTS 27

REFERENCES 27

Evolutionary theory was first applied to the behavioural sciences by Darwin (1871, 1872). Since then the field of evolutionary behavioural science has blossomed. The history of this field is detailed and well-rehearsed within the literature (e.g. Buss, 2008; Dennett, 1995) and it would not be possible to do it justice within the confines of a chapter. Instead, this chapter will introduce a particular perspective on evolutionary behavioural science in the hope that it will act as a stimulus to discussion and help the reader to unravel subsequent chapters in this volume. Inevitably, there is some historical detail in order to contextualise certain points, but this chapter is far from a complete history. I hope that historically minded readers will forgive this.

This volume is about evolutionary psychology, but I have chosen to write a chapter about evolutionary behavioural science. Psychology is, of course, a behavioural science and much activity within the discipline is solely about measuring behaviour. However, psychology is also interested in endocrine, neurological and cognitive mechanisms that all cause behaviour, and these mechanisms are discussed in computational or information-processing terms. These mechanisms can be said to mediate inputoutput relations, with the final outputs being behavioural. Evolutionary theory is used in order to discuss the functions of behaviour – what any given behaviour is designed to achieve – and to determine the functional limits for underlying psychological mechanisms. Evolutionary theory, then, gives us an ultimate explanation (Tinbergen, 1963) that helps us to develop accounts of the kinds of proximate mechanisms that constitute, in this case, the psychology of an organism; it does not tell us the detail of those mechanisms, which is a task left to the proximate methods of the discipline of psychology. This chapter discusses the breadth of this application, hence its focus on evolutionary behavioural science as a whole.

Evolutionary theory is a theory of design. Before moving on to discuss the process of evolution, it is important to clarify this key notion of design. Design is not confined to organic life, and an unnatural example will help to abstract the fundamental features of this concept. Think of a simple robot with the task of moving across a room whilst avoiding various obstacles (see Dickins and Dickins, 2008, for a fuller treatment of this example; and also Braitenberg, 1984). One possible design for such a robot would be based around a simple car chassis. It would have four wheels, two at the front and two at the back. The back wheels would be attached to a motor each, to power them independently. At the front of the robot, there would be two depression paddles. The left paddle would be connected to the back right motor; the right paddle would be connected to the back left motor. These connections would be inhibitory, such that depressing the left paddle would stop the right motor. As the left motor is still going, the robot would turn to the right (see Figure 1.1). In the same way, depressing the right paddle would cause the robot to turn left. In this way, obstacles would be avoided and the robot could continue its travels across the room.

The robot clearly has a function and has been designed, by an engineer, to meet this function. The depression paddles are an essential part of this design for they are the robot's only source of inputs from the outside world and, to this extent, they act as a sensory system. The only knowledge this robot has of the outside world, through which it has to move, is through these paddles. To this end, its only experience of the world is tactile and such inputs are the only inputs of any importance. The robot could be bathed in light and sound but such things will have no effect because the robot has not been designed to use them.

There is much discussion about the relationship between function and knowledge in the philosophical literature (e.g. see Millikan, 1993). I am using the term loosely in this chapter to imply a meeting of design and environment such that the robot, in this case, can deliver its functions. So, if a design provides a good fit to the environment the design embodies facts about that environment and in this sense represents something about the environment. This relates to the difference between environment and ecology that is mentioned later. I am not seeking to discuss notions of content, concepts, meta-representational states and all else associated with high-order cognition. However, the astute reader will realise that there is a relationship to be drawn out.

We can characterise the robot's design as a series of conditional rules, such that the robot's architecture embodies a number of possible decisions. Informally, we can say:

If (P1: the right paddle is depressed) then (Q1: turn left) If (P2: the left paddle is depressed) then (Q2: turn right)

These conditional rules can readily be translated into more technical terminology that captures the actual mechanical actions made to move from P to Q. This may appear superfluous or, worse still, an exercise in artificial formalism. It is certainly a simple point that this robot can be described in this way. However, the point extends to all organisms and all biological systems. Think of a bat; bats navigate and hunt using echolocation. They emit pulses of sound and listen for a returning echo in order to locate the distance and direction of moths. Distance is easy enough to calculate as sound travels at a constant speed; so, simply timing the duration from utterance to received echo and then dividing it by two will give the distance. Bats have cognition that enables them to calculate the distance and, to some extent, you could argue that bat cognition encompasses this simple mathematical algorithm; it represents a truth about the world.

Bats determine direction of prey by calculating whether the echo reaches their right or left ear sooner. Folds within the ear help to determine the vertical positioning of the bat owing to the angle at which the sound hits the ear. Smaller objects reflect sound less intensely than larger ones and inbuilt knowledge of the sizes of suitable prey determines whether the bat will treat the echo as indicative of food. The sounds that bats emit are at very high frequencies, often too high for human ears. They are also at extremely loud volumes – indeed, if they were within the human frequency range but at the same volume, they would be damaging. This is clearly an issue for the bats. To counter this, they temporarily deafen themselves whilst emitting the sound, and then switch their hearing back on to receive the echo.

There is more to say about the biology of bat echolocation (see Altringham, 1999), but from this account you can see that we are dealing with systems that deliver outputs and that they are describable in terms of decision rules. So, for example, horizontal location during hunting can be characterised as follows:

If (P1: left ear input first) then (Q1: dip left wing and raise right wing)

Bats, just like robots, are clearly designed to process inputs and deliver outputs. When we discuss bats, we might refer to them as processing information about the outside world in order to navigate and hunt. That information is processed by conditional systems, and the relationship between the inputs and the processing systems captures truths about the world. Note that `information' refers to the functional relationship between an input and a system. If the system is designed to take this input, designed to have a conditional response, then the input is informative. If not, then it is an empty input. Information is not something in the world to be captured; it is a consequence of design.

Bats, unlike robots, have no engineer, no designer who has intentionally built them to capture moths. To this end, we need an account of the design of organic life that does not rely upon any kind of agency: evolutionary theory delivers this.

A BRIEF INTRODUCTION TO EVOLUTIONARY THEORY

Darwin's interest was in the diversity and variation found in life. He noted that the various traits he observed in species appeared fit for purpose, as if they were designed to do a specific job, and he sought to explain this. His explanation was the theory of evolution through natural selection.

The Darwinian view sees organisms as engaged in a struggle for life. They face numerous problems that can deleteriously affect their survival and reproductive chances. However, the heritable traits that organisms possess can help them to solve these problems and, if this happens, those traits can be passed onto their offspring. As traits vary between individuals, such that one individual may deliver a solution to a problem more effectively than the next, some organisms thrive relative to others. Those with a variant of a trait better suited to the struggle for life are more likely to survive and to reproduce than those with less-well-suited variants, and gradually this 'better' variant will come to dominate in the population because of its heritability. Just so long as the problem remains a stable aspect of the environment, this variant will reach fixation.

It is the problems of survival and reproduction that provide selection pressure for particular variants. Natural selection is, therefore, an economic consequence of the interaction between problems of survival and reproduction and heritable traits. Those traits that are selected can be termed 'adaptations'. Darwin's own formulation of the natural selection of adaptations can be distilled into a number of key principles. First, the principle that there is a struggle for life, an idea seeded by Darwin's reading of Malthus's (1798) An Essay On the Principle of Population, in which the consequences of geometric rates of reproduction relying upon finite, and at best gradually linearly increasing, resources, were discussed. Malthus's stark prediction was that population growth will exceed resources and will then be checked by famine, disease and war. The second principle is that of trait variation. From these Malthusian catastrophes, some individuals will emerge and continue their lives. The traits that enable them to survive can be passed on, which is the third principle of inheritance. Darwin draws the three principles together in the following passage of The Origin (1859/1985, pp. 169–170):

If during the long course of ages and under varying conditions of life, organic beings vary at all in the several parts of their organisation, and I think this cannot be disputed; if there be, owing to the high geometrical powers of increase in each species, at some age, or year, a severe struggle for life, and this certainly cannot be disputed; then, considering the infinite complexity of the relations of all organic beings to each other and to their conditions of existence, causing an infinite diversity in structure, constitution, and habits, to be advantageous to them, I think it would be a most extraordinary fact if no variation ever had occurred useful to each being's own welfare, in the same way as so many variations have occurred useful to man. But if variations useful to any organic being do occur, assuredly individuals thus characterised will have the best chance of being preserved in the struggle for life; and from the strong principle of inheritance they will tend to produce offspring similarly characterised. This principle of preservation, I have called, for the sake of brevity, Natural Selection.

The Origin was published on 24 November 1859, and the impact of this elegant process of selection was immediately felt. Darwin had provided an explanation for design that required no hidden hand, no grand designer, and he demonstrated this through detailed and exhaustive natural history. What was lacking, however, was a theory of inheritance; how were traits passed on from generation to generation in a manner that would permit selection to do its work?

Many histories of Darwin (see Dennett, 1995) note that he had not read Mendel's paper on particulate inheritance published some two years before The Origin. One can only speculate as to how Darwin might have put this to use, although Darwin was not alone. Mendel's work on garden peas and other plants, and his notion of inheritance, was effectively ignored until the twentieth century, when chromosomes became the focus of attention for research on heredity (see Fox Keller, 2000). Then, in 1953, the structure and character of DNA was revealed, with the authors of that key paper laconically noting at the end that their discovery may have some impact upon theories of heredity (Watson and Crick, 1953). Genetics had come of age.

Genes code for proteins, and in so doing build traits; genes vary in trait expression and genes are inherited. What is more, genes can become altered through mutation and in this way new trait variation can be introduced. Monod (1972) famously described evolution as a process of chance and necessity. Mutation is the main aspect of evolution that is reliant upon chance. Once a beneficial mutation is produced, that gives some competitive advantage in the struggle for life, selection will 'take hold' of it and this blind process will take that trait to fixation within a population.

During the 1960s, much theoretical work made it clear that selection at the level of the gene best explained the main effects of evolution. Genes could be conceptualised as functionally eternal, replicating themselves through the generations just so long as natural selection permitted it. In this way, an adaptation was defined as any trait that causes its underlying genes to increase in relative frequency within the gene pool. Dawkins (1976) captured the essential logic at work in his book The Selfish Gene. Genes were to be seen as self-interested, seeking their replication through the vehicles that carried them. If this replication is best served by building traits that make the organism bearing them selfish, then selection will see to it. Equally, if it is beneficial to build organisms that cooperate to attain resources, then genes for cooperation will be selected for. Nothing in selfish gene theory implies selfish behaviour in the organisms carrying those genes.

This theoretical innovation had fruitful consequences. First, it has been possible to separate biochemical accounts of molecular genetics from functional discussions where it is useful to talk of genes for a particular trait (Haig, 2006). Second, it allows genes to be seen as strategists, and their strategies, their traits, account for the changes in gene frequencies over time. In the final analysis, a complete biological science will provide the full biochemistry but evolutionary biology can productively move forward without this knowledge. These consequences were mathematically realised in the form of evolutionary game theory (Maynard-Smith, 1982). Traits, as competing strategies, could be modelled to see which would come to be stable over time, such that they could not be shifted by the arrival of a new mutant strategy, even if other strategies could survive in the population (so-called evolutionarily stable strategies; see Box 1.1).

The biochemistry of genes does have some theoretical impact. Genes are best understood as functionally described portions of DNA. Their function is to build polypeptide chains, that later become enzymes or proteins, or to control the expression of other genes. During protein synthesis, DNA unravels, the code is transcribed and translated through the action of various types of RNA, leading to the formation of a polypeptide chain (see Box 1.2), which is folded into a protein. In the now classical formulation, information is regarded as flowing in one direction only, from DNA to protein. There is no information flowing back from the protein, or any other intermediate stage in the process, to the DNA. In other words, DNA is unaffected by the subsequent stages of the process. This is known as the 'central dogma of molecular biology' (Crick, 1970).

The central dogma effectively deals with a view often referred to as 'Lamarckian evolution': the idea of the inheritance of acquired characteristics as formulated by Jean-Baptiste Lamarck. If information only flows one way in order to synthesise a protein, in order to build a trait, then whatsoever happens to that trait later in terms of its development cannot affect the substrate of inheritance. So, the children of a weightlifter will not be born with bigger muscles as a consequence of their father's exercises. If he is successful at weightlifting, it is likely that he has genes that build muscles with a lot of developmental scope. His children may well inherit these genes, and if they exercise too they will resemble him in this trait, but they have only inherited the predisposition to develop muscle in a certain way.

(Continues...)

Excerpted from Evolutionary Psychologyby Viren Swami Copyright © 2010 by John Wiley & Sons, Ltd. Excerpted by permission of John Wiley & Sons. All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.
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Edition details

• Publisher: BPS Blackwell
• Publication date: 2011
• Language: English
• ISBN 10: 1405191228
• ISBN 13: 9781405191227
• Binding: Paperback
• Edition number: 1
• Number of pages: 392
• Editor: Swami Viren