Understanding Psychology at A level and GCSE: 3


Here is the third in our new series of Psychology blogs – useful for anyone revising for exams or thinking about taking up Psychology as a new subject at A level or GCSE.

Why do we need Experiments in Psychology?

Psychology is the study of the mind and behaviour of humans and animals.  So why do we need to conduct experiments in the study of psychology?

Well, psychology is not like physics or chemistry. In chemistry, we might do an experiment and put chemical A with chemical B and in our result, C happens.  We can’t do that with human beings, first because, in some circumstances, it is unethical to experiment on humans in this way, and secondly, because psychology is not an exact science.   We couldn’t give a human being a drug and expect it to have the same effect on everyone. All humans are different. We have different genes and different experiences. All of these affect how we respond to situations.

So if we were to give drug A to person A, they may become sleepy. If we were to give drug A to person B, they may become anxious and so on. So we carry out experiments in psychology to see how people generally behave to situations. We cannot perform experiments on animals and humans and definitely say that all humans or animals will perform in the same way. All we can say is things like –

When we give a person Drug A, in 95% of the cases, they will become sleepy.

We would find it very hard to say that 100% of people would perform in the same way.

We all think we understand why people behave the way they do. We are told that people move their eyes in a certain way when they lie, that babies go through certain stages as they age and develop, that our memories work in certain ways. But how do we know this?

We conduct scientific experiments to try and determine what kinds of people behave in certain ways, and what affects their behaviour.

Memory is an area of human behaviour  in which a lot of experiments have been carried out.

For example, how can we find out if being distracted affects our memory? I might think “Yes, distraction affects my memory”, but what if I am unusual? What if distraction doesn’t usually affect people’s memories?

We could conduct an experiment to test whether distraction affects our ability to recall information. So we may ask 1000 people to remember a list of 50 words. We might give the words to 500 people, then let them sit for two minutes, then see how many words they recall. With the other 500 people, we may give them the words, then for two minutes ask them to say their times tables from 1 to 12, then ask them to recall the words. We would then compare the results.

If Group 1 recalled more words than Group 2, this would suggest that distraction affected the memory of the second group.

If Group 1 and Group 2 had similar results, this would suggest that distraction didn’t affect the memory of the second group.

Of course, if we study 1000 people, we are not testing the whole human race. It would be hard to carry out an experiment on everyone. By studying 1000 people, we can get a better idea of whether distraction affects recall.

So in answer to the question ‘Why do we need experiments in Psychology?’, this example shows how we can test for general patterns in behaviour among groups of people and establish what generally happens in a controlled situation.

See my next blog for another experiment on memory.

Tracey Jones

Psychology Tutor, Oxford Open Learning

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