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Behaviour, Development and Evolution

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Patrick Bateson

11. Concluding Remarks

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1Two themes have run through this book about the development and evolution of behaviour. The first has been about the adaptive processes that give rise to the appearance of design in nature. The second has been about systems, the active role of the organism and the different factors that influence development and evolution. These themes are relevant to human development and some chapters are almost exclusively devoted to human examples.

  • 1 Narvaez, D., Valentino, K., Fuentes, A., McKenna, J. & Gray, P. (2014), Ancestral Landscapes in Hu (...)
  • 2 The origins of violence in human society involve many inherited dispositions or adverse experience (...)

2Not all behaviour is adaptive in the present. In humans the dietary preferences that were adaptive in the past, such as those for salt and sugar, can seriously disrupt health when these substances are readily available.1 Gambling, which sometimes ruins lives, can seem irrational but makes sense in a world in which the delivery of rewards is rarely random. If you have done something that produced a win, it is usually beneficial to repeat what you did — except when you get into a casino. Similarly, the tendency of parents to protect their children from all contact with unknown people after hearing from the media of a child murder would have been beneficial in a small community where such news might represent real danger. In the modern context, such risk-averse behaviour in a society in which the incidence of child murder has remained constant for decades merely impoverishes the child’s development. Even though they were once adaptive, the emotional responses of parents can now have adverse effects on their children’s lives.2

3The appearance of design can generate misconceptions. Even so, when a process like behavioural imprinting is examined, it is reasonable to suppose that it plays an important role in the development and survival of each individual bird. Understanding the rules that underlie the development of the individual and the reciprocity between those rules and the individual’s experience is important in making sense of the complexity of development.

4The young organism has to deal with many challenges that meet it as it develops. Its ecology may be very different from that of the adult, in which case it may have special adaptations to deal with those conditions. Like a caterpillar metamorphosing into a butterfly, a human child has adaptations to deal with each stage of its life cycle. The prevalence of play in the young is an example.

5Despite the changes in the individual’s repertoire of behaviour as it grows up, early experience can have long lasting effects on its preferences and habits when it finally matures. These aspects of its behaviour are often stable, but in stressful conditions they may change when the stress is accompanied by new forms of experience. The change can be adaptive since it can enable the individual to cope with a world that may be very different from the one in which it grew up.

6In mammals, parent and offspring are often thought to be in conflict. On this view, the communication between them takes the form of mutual manipulation. The offspring seeks to gain maximum advantage from its parent and the parent seeks to defend its long-term reproductive interests. Against this view, communication is often such that both the sender and receiver of a signal or cue may benefit by both parties treating it as useful to themselves. In the case of parent-offspring relations, parents do well to take into account the condition of their offspring and the offspring must likewise pay attention to the condition of their parent. In other words, their behaviour is adaptive for both parties.

7Many animals choose their mates carefully. This is especially true in birds and many mammals. Inbreeding has costs but so too does excessive outbreeding. The way in which an optimal balance is achieved is in part through experience with close kin in early life leading to a preference for a mate who is a bit different but not too different from familiar kin. An important issue is whether the avoidance of incest found in most human societies serves the same function as the avoidance of inbreeding. A common function is questionable and the taboos or more likely to be an expression of conformism directed at individuals doing what most people would not do.

8With the great successes of molecular biology, attention has been focused on the role of genes in development. Genes are unquestionably needed for the inheritance of much behaviour. The importance of genes, however they are defined, does not mean that a simple link can be found between genes and behaviour. The links are usually complex and metaphors such as genes providing a blueprint for behaviour are misleading. The benefits of the selfish gene approach in understanding the complexities of evolution do not imply that genes program the development of an individual. Understanding development requires a systems approach that takes into account all the genes and environmental inputs that are effective.

9Development and evolution are usually regarded as separate domains of inquiry. Even so an organism’s adaptability provides a useful link between these domains. It offers understanding of the relationship between what an individual does and how its activities might influence the genomes of its descendants. Many theoretical arguments have been used to explain how this might happen and some empirical evidence supporting these arguments is becoming available.

10The notion of genetic determination, which is so firmly embedded in evolutionary theory, has seriously interfered with attempts to understand the dynamics of behavioural development and its role in evolution. If anything has been learned in recent years, it is that what an individual animal does in its life is conditional and depends on the reciprocal character of the transactions with the world about it. This knowledge also points to ways in which an animal’s own behaviour can provide the variation that influences the subsequent course of evolution. When developmental issues are joined with questions about evolution, it becomes easier to perceive how an organism’s behaviour can initiate and shape evolutionary change.

11These changes in biological thinking affect the relations between the natural and the social sciences. The biggest block to bringing the biological and social sciences together was the presumption that Darwinian evolution implied genetic determinism. This block has now been removed by advances in biological thought (see Chapter 8). Behavioural biologists have sometimes misleadingly applied terms such as ‘greed’, ‘spiteful’, ‘rape’, ‘marriage’ and ‘incest’ to animals. This may have been done to lighten the normally dull language of scientific discourse. However, these terms have an established usage in describing human emotions, and in describing human institutions with all their associated rights, individual responsibilities and culturally transmitted rules on what people may and may not do. Problems of communication between disciplines have been compounded when, having found some descriptive similarities between animals and humans, and having investigated the animal cases, biologists or their popularisers have used the animal findings to ‘explain’ human behaviour. Such arguments rely on a succession of slippages in meaning and are usually unconscious, but they provoke hostility in those people in the social sciences and humanities who feel threatened by an apparent take-over bid on the part of biologists. An example of how the effects of early experience promoted by biologists have been misconstrued by the social scientists is described in Chapter 5.

12The conflicts of motivation evident in studies of animal behaviour bear on important issues to do with human behaviour. In many social contexts a person might weigh up consciously or unconsciously the benefits to themselves of behaving in a particular way. The benefits might include avoiding disapproval or punishment by other people. However, all these dispositions can conflict with powerful impulses to act in ways that benefit the social group, the tribe, or some larger assemblage without any direct benefits to the individual. They may cooperate with individuals they regard as belonging to their own social group and express fear or hate of those individuals they regard as being different or foreign. They may be influenced by their desire for leadership and strongly disapprove of anybody who does not conform with their views. None of these impulses are invariant. They can be, and often are, changed by experience. Conformism and the expression of fear and hate can be inhibited, or modified either by social norms or by becoming aware of the damaging consequences of allowing full reign to such impulses.

13By bringing together evidence from different areas of knowledge, more powerful theoretical perspectives can be formulated. Their impact is not only on scientific approaches to the systems of development and evolution, but also on how humans change institutional rules that have become dysfunctional or design public health measures when mismatches occur between themselves and their environments. It affects how humans think about themselves and their own capacity for change. The biological approach to human psychology does not imply that individuals do not have free choices. Through their decisions individuals clearly do make a big difference to what happens in their lives. They may be sometimes surprised by the consequences of their own actions. Even so, they are able to anticipate the consequences of various courses of action and choose between them on the basis of their likely costs and benefits. Planning before doing is clearly of great advantage. The evidence stares us in the face. People do make wellconsidered decisions and they benefit from doing so.

Notes

1 Narvaez, D., Valentino, K., Fuentes, A., McKenna, J. & Gray, P. (2014), Ancestral Landscapes in Human Evolution: Culture, Childrearing and Social Wellbeing. New York: Oxford University Press.

2 The origins of violence in human society involve many inherited dispositions or adverse experiences in early life. The consequences of these developmental abnormalities are expressed as harmful or psychopathic behaviour already, before the age of three, and may persist throughout life. However, in a humane society much can be done to help such troubled people by identifying them early on, giving their parents extra support, treating them with sensitivity and not punishing them for bad behaviour. They need not be treated as irredeemable and effectively given a life sentence. An excellent discussion of the origins of anti-social violence is given by Adrian Raine (2014), The Anatomy of Violence: The Biological Roots of Crime. London: Penguin Books.