What Is Psychology?

Psychology is the science of mind, behavior, and experience. It attempts to explain why humans and non-humans behave in the way they do, and to support the explanations with objective evidence.

The term science refers to the objective study of something. Psychologists study behavior—what people (and other animals) do. Behavior includes being aggressive or kind, thinking and seeing, breathing and walking, growing up and getting old, being a friend or a parent, and so on. These are all examples of “behavior”.

Psychologists are also interested in “experience”. If we want to understand behavior we also need to consider what the experience is like for the individual doing the behaving. For example, if we want to study aggression, it matters what the person who is behaving aggressively feels like.

Psychology is concerned with the study of all human and non-human animals. However, this literature is oriented on the study of human behavior.

Is Psychology Just Common Sense?

Many people say “Well, psychology is only common sense!” Everyone is an “armchair psychologist”. We all have views about why people behave as they do and, in a sense, these are “theories of psychology”. For example, your friend might say “Those football fans act like that because they’re hooligans”.

By saying “They’re hooligans” your friend is presumably offering an explanation for the fans’ behavior, such as “They have no care for the feelings of others”. But how do we know this explanation is correct? That’s the starting point for psychological research. Psychologists observe behavior, put forward an explanation or theory to account for the behavior, and then conduct a test to see if their theory is correct.


As an example, ponder this scenario:
Several years ago, a young woman was stabbed to death in the middle of a street in a residential section of New York City. Although such murders are not entirely routine, the incident received little public attention until several weeks later when the New York Times disclosed another side to the case: at least 38 witnesses had observed the attack—and none had even attempted to intervene. Although the attacker took more than half an hour to kill Kitty Genovese, not one of the 38 people who watched from the safety of their own apartments came out to assist her. Not one even lifted the telephone to call the police.
(From A.M. Rosenthal, 1964, Thirty-eight witnesses. New York: McGraw-Hill.)

Two psychologists John Darley and Bibb Latané (1968) read this report. It made them wonder, “Why do bystanders in an emergency fail to offer assistance?”

The common-sense answer, given by the New York Times, was that city dwellers were a callous and uncaring lot of people. Darley and Latané thought that perhaps the reason was related to the number of bystanders—in this case there were 38 “silent witnesses”. Could it be that each individual witness assumed someone else was taking action to end the emergency situation and therefore they personally didn’t need to do anything?

Up to this point you might say that Darley and Latané’s thinking was not necessarily more than common sense (although it was an unusual explanation). But what they did next is what distinguishes psychology from common sense. They set up an experiment to test their opinions—they arranged for students to discuss personal problems with each other over an intercom. Except that there was only one actual student involved: the other participants were confederates of the experimenter pretending to be participants.

During the conversation, one of the “students” appeared to have an epileptic fit. If the real student was under the impression that five people were listening to the conversation it took them three times longer before they offered help than if they thought there were only two people.

This study appears to demonstrate that it is the number of people present that affects how likely one is to offer help in an emergency situation. This is psychologythe attempt to explain why people behave in the way they do, and to support these explanations with objective evidence.

In sum, psychology is more than common sense because psychologists conduct and apply research and use research-based evidence to support their theories. Their research aims to achieve a balance between validity and a good control of irrelevant factors.

Branches of Psychology

A number of psychologists conduct research into different branches of psychology, such as the core areas of cognitive, developmental, physiological, individual differences, and social psychology.

Other psychologists may apply this research in areas such as health, business, crime, and education, and some work as clinical psychologists helping with mental disorders.

We’ll spend the remainder of this literature briefly addressing these core areas of psychology.

  1. Cognitive psychology

Cognitive psychologists focus on topics such as memory, perception, thought, language, attention, and so on. They are interested in mental processes and seek to explain behavior in terms of these mental processes, in other words.

There are many applications of cognitive psychology, ranging from suggestions about how to improve your memory (useful for examination candidates!) to how to improve performance in situations requiring close attention (such as air traffic control).

  1. Developmental psychology

Developmental psychology is a branch of psychology oriented towards the changes occurring over a person’s lifetime, starting from conception and infancy through adolescence, adulthood, and finally old age. This approach has also been called lifespan psychology.

Developmental psychologists focus on how particular behaviors change as individuals grow older, for instance, they look at the changes in the way children think. They also look at how children acquire language; at moral, social, and gender development; and at changes such as coping with retirement or with memory loss.

  1. Physiological psychology

Physiological psychologists are interested in how to explain behavior in terms of bodily processes. They look at topics such as how the nerves function, how hormones affect behavior, and how the different areas of the brain are specialized and related to different behaviors.

Physiological and psychological explanations
Neurology and biochemistry underlie all behavior. What happens when a person sees a sunset? The physiological explanation would be that light reflected from the landscape forms an image on the retina, which is converted into a neural signal and transmitted to the brain, and so on. No-one disputes that this is true, and the process is absolutely essential, but does it give a full and adequate explanation of what is going on? A psychological explanation would probably include the personal and social relevance of the experience, which many would argue are of equal value.
(From Michael W. Eysenck, Psychology for AS Level.)
  1. Individual differences

The study of individual differences is literally the study of the ways that individuals differ in terms of their psychological characteristics, for example, intelligence, aggressiveness, willingness to conform, masculinity and femininity, and just about every behavior you can think of.

An important individual difference can be found in the degree to which a person is mentally healthy. This is specially referred to as the study of abnormal behavior and forms the basis of abnormal or atypical psychology, which studies childhood and adult disorders such as dyslexia, autism, schizophrenia, and depression, seeking to find explanations and valid methods of treatment.

  1. Social psychology

Social psychologists are interested in the way people affect each other. They look at, for example, interpersonal relationships, group behavior, leadership, majority and minority influence, obedience to those in authority, and the influence of the media.

Social psychology differs from sociology in placing greater emphasis on the individual as a separate entity; sociologists are interested in the structure and functioning of groups, whereas social psychologists look at how these processes influence the individual members of a social group.

  1. Other branches of psychology

The five areas just described form the core of psychology, but there are other areas of psychology as well. For example, comparative psychology is the study of non-human animals—comparisons are made between animals of different species to find out more about human behavior. The study of animal behavior is a field of study in its own right and straddles psychology and biology.

Keep on learning:
  1. M. W. Eysenck (1994) Perspectives on psychology (Hove, UK: Psychology Press).
  2. A. E. Wadeley, A. Birch, and A. Malim (1997) Perspectives in psychology (2nd Edn.) (Basingstoke, UK: Macmillan).
  3. J.C. Berryman, D.J. Hargreaves, C.R. Hollin, and K. Howells (1978) Psychology and you (Leicester, UK: BPS Books).
  4. C. Tavris and C. Wade (1997) Psychology in perspective (New York: Longman).
  5. W.E. Glassman (1995) Approaches to psychology (Milton Keynes, UK: Open University Press).