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1. Introducing psychology(6)


In other words, we can look at the same thing using different levels of explanation.  One psychologist studying reading might use a very general level, such as looking at cultural influences on human behaviour. Another might approach it at the level of social influence, by looking at how family or similar groups affect what we do, and also how we conform to social expectations – or don’t, as the case may be. Some psychologists might look at it in terms of personal habits and past experiences, while others would seek to understand how the visual information is processed in the brain. All of these, and many others, are levels of explanation that we can use in our attempt to understand human beings. Psychologists know that no single level of explanation is going to enough in itself, but researchers focus on one single level in their work because trying to deal with everything all at once would simply be too much.



Emergent Properties


Understanding everything about one level of explanation couldn’t give us the whole answer, because each level of explanation is more than just the sum of the lower level. Sometimes, for instance, you hear people claiming that once we know about all the different nerve cells in the brain, then we will know all there is to know about how the brain works. But this isn’t true, because there are often entirely new properties which emerge when the different parts are combined into a whole system. And these emergent properties can make all the difference.



Perhaps this will be clearer if I take an everyday example. A cake is made up of everyday ingredients: flour, egg, butter, and so on. To understand what a cake is, you would have to know about these. But knowing about them wouldn’t tell you everything about the cake, because a cake has properties which the single ingredients on their own don’t have. At the simplest level, it has a taste and texture which are not present in the single ingredients. At higher levels, it may have cultural or symbolic significance. It might be a birthday or a wedding cake, or symbolize a particular religious festival. None of these can be deduced simply by studying the ingredients.




It’s same with human beings. We can learn a great deal about people by studying the brain and how it works, but we can’t learn everything. We may be able to trace which nerve cells in the brain are active when we are solving a problem, but this doesn’t tell us how we are working out a solution, or why we are thinking about the problem in the first place. We need to bring together as many levels of explanation as possible, and to study the emergent properties of each new level, to make any sense of the human mind.



Table 1.1 shows some of the main levels of explanation which psychologists use in analysing problems. A professional psychologist, dealing with real people, needs to be a aware of how all of these levels of explanation interact. This is partly why professional training as a psychologist takes so many years. Academic psychologists, though,use a more limited number of levels of explanation at any one time, because they are trying to analyse and understand psychological processes, rather than whole people.



Understanding the individual person, then, is a pretty massive task, and it would be unrealistic to think we know everything there is to know. When it comes to human beings, there aren’t any easy answers. After reading this book, you won’t find that you can understand everyone you’ve ever met. But what you will find, I hope, that you know a great deal more about people than you knew before, and you may also find that it sometimes helps you to understand the people around you a little better.



Table 1.1 Levels of explanation


Cultural influences 文化的影響

Socio-political influence 社会政治的影響

Subculture and social status サブカルチャーと社会的ステータス

Social cognition 社会的認知

Social groups, family etc. 社会的グループ、家族、その他

Interpersonal interaction 対人行動

Intentions and motives 意図と動機

Cognition and emotion 認知の感情

Habits and learned associations 習慣と学習

Genetics and evolution 遺伝と進化

Physiology 生理学

Cellular biology 分子生物学

Organic chemistry 有機化学

Quantum physics 量子物理学