The book reviewed here is Introducing Evolutionary Psychology by Dylan Evans and Oscar Zarate. I’ve read a number of the books in this series and have enjoyed them. The simple approach to explaining complex topics is very successful especially when combined with the sometimes tongue-in-cheek illustrations. It’s a bit like reading a comic! Having said that, one of the graphic illustrations may offend some of the more conservative readers.
The reader is taken through an overview of cognitive psychology and evolutionary biology. This sets the scene for the remainder of the book. The problems of adapting to the environment are divided into a number of categories (avoiding predators, eating, forming friendships, helping relatives, mind-reading, communicating, selecting mates). These are then worked through later in the book.
The idea that the brain consists of modules each performing a certain function, I find to be a little too simplistic. For instance it should be possible for some redundancy in the brain – which means that if there is injury – functions will still be possible by recruiting other parts of the brain. Similarly tasks do not have a single solution but instead there are many possibilities. In my opinion therefore, it is more sensible to talk about many-many mappings of brain-function. A clear cut example is as follows. Suppose I need to reach out for a cup in front of me. I can do this with my eyes open. Then its very easy – I just reach out for the cup. However if I want to repeat the same action with my eyes closed I need to adapt a different strategy – feeling around on the desk for the cup. If I add another constraint – that I should touch the cup – then I will look around for an object to pick the cup up with. Each of these cases illustrates a different strategy. Yet when I have my eyes open I am clearly using visual cortex areas to help achieve the goal. The same is true of functions, for instance does it make sense for me to have a lion evading module? This would be silly. There are only a few parts of the world where lions pose a risk but in different parts of the world there are other creatures which are just as dangerous. Thus it would be more sensible to be able to recognise these creatures, make a study of them, pass this information within the group and predict their actions. Before getting into a dangerous situation, there would be a number of warning signs. The dangerous animal would be visible, it would produce a sound, it would leave markers on its territory. A person would develop an awareness of the animals living in its neighbourhood, just as the person develops an awareness of other members of their group. Perhaps something is going wrong if they are getting to the stage where their fight-or-flight response is activated without very little warning. In this situation, to me, it makes more sense to have a strategy for reducing risk rather than a circumscribed module specifically for avoiding predators. This strategy would invoke generic cognitive apparatus for planning. The modular argument is perhaps more successful for functions such as sensory processing.
The discussion of food selection has relevance to changing patterns of obesity in the population and focuses on areas such as fat and sugar consumption. The free rider problem crops up within groups. The idea is that there can be free riders in a social group who consume but do not contribute. If the group allows these free riders to procreate, the society will become less productive. However, it does not follow that if there is a ‘free rider’ their offspring will be ‘free-riders’ too. Instead it is necessary to move away from genetic determinism and consider the environment a ‘free-rider’ will produce for their offspring. By definition, they will be providing little if anything to their offspring and we would expect their surviving offspring to become ‘self-sufficient’. Of course, in the end, we need research evidence to confirm or refute this speculation. A difficulty with the altruism/social-exchange paradigms is that the computer simulations are often too simple and would be better suited to predicting the behaviour of unicellular organisms rather than people who have more flexible strategies for producing behaviour. However, the tit-for-tat theory of social exchange appears to have ecological validity.
The relatedness theory suggests that people relate more to others with a similar genetic make-up. The idea is that a gene selected at random will be shared in two related people. Here we must however recall that the gene is just the first part in a process which includes activation of the gene, transcription into RNA, conversion into a protein and addition of sugars together with transportation to the functional destination. Nevertheless, it is hard to argue with this possibility when we consider the case of identical twins.
The section on parental care and human brain size is interesting and relates to the recent paper by Feeley on the relevance of Freud to modern psychiatry. Feeley discussed the rapid increase in size of the brain during the first two years of development and the critical interactions with the parents that occur during this time. The authors note that there were two ‘spurts’ in brain volume increase in human evolution – the first was 1.5-2 million years ago and the second was 200,000 to 500,000 years ago. The increase in brain volume, means a longer period of development during which time one parent would not be expected to be able to cope alone. This leads onto the need for longer-term partnering strategies. Whilst it is speculative, it is tempting to suppose that these sudden increases in brain volume took place in environments and cultures which allowed for investing more resources in offspring (and that it resulted not just from a single gene change but perhaps a chromosomal change or epigenetic phenomenon).
The book finishes with some criticisms of the presented model. The absence of a reading module and the need for economy in attributing adaptive features are pertinent points. I found myself questioing the Wason-Selection Task which shows that people are better at solving cognitive tasks if the goal is to detect cheats. The results might be better explained by supposing that people are inherently better able to frame and solve problems in terms of relationships.
This book is a good introduction to the field and makes a number of concepts very accessible.
Evans D and Zarate O. Introducing Evolutionary Psychology. (Re)Published 2000. Totem Books.
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