Why is Psychology a Science? Part 1: Defining Characteristics

Last updated on June 6th, 2020 at 07:49 pm

Everyone is an armchair psychologist.  Most of the humans I know love to people watch. We like to invent our own theories about why people do the things that they do. ‘Bob eats so much because he has low self-esteem. Hattie is so loud at parties because that is part of her personality.’ But, the general ideas that we have about behaviour, both as individuals and a society, do not always turn out to be true. Milgram’s (1963) study was a classic example; we did not believe that someone would be capable of delivering electric shocks to another person, but in the right conditions those people obeyed and did exactly that *. So, while it can be fun to have our own opinions about the causes of our behaviour, we need a more rigorous approach to help us to establish the facts.  By using scientific methods such as experiments, psychology has established itself as a more trustworthy and reliable source of information about ourselves.

When I was new to studying Psychology, I wished that I had read a similar article to the one I have written here. At college, I would inevitably encounter students of different subjects areas who would downright scoff at the idea of ‘science’ and ‘psychology’ being used together in the same sentence. I felt in my gut that they did not know the whole story. But at the time I just could not find the words to back up my beliefs.  This was incredibly frustrating for me as I was so passionate about my view!

Humans are incredibly complex creatures. Discovering the precise causes of behaviour in any given moment can seem like an impossible task. There are so many factors that could be involved. Biologists can show us that the heart pumps blood around the body. They have cold hard evidence to back up their theories. Psychology doesn’t always have this advantage. You cannot see ‘the mind’, so how can we demonstrate that it has an impact on our behaviour? This is probably the reason why some individuals are sceptical of a scientific approach to psychology.  But the majority of fields within psychology are most definitely a science!  And I hope to convince you of this by the end of this series.

How do you define a ‘science’?

Good question! The short answer is, there is no universally accepted definition. The Oxford Dictionary defines a science as “The intellectual and practical activity encompassing the systematic study of the structure and behaviour of the physical and natural world through observation and experiment.”

This definition offers a good starting point. It introduces some key terms such as “systematic study” and “observation and experiment”. But I do not think it is specific and detailed enough to explain what a science consists of.

Applied Behavior Analysis, a book by Cooper, Heron and Heward (2007) walks through the characteristics which they believe defines a science. They clarified the characteristics of a science in a way that completely made sense to me. Their book is in a context of a behavioural approach to psychology, but I feel that their definition is objective enough to transfer to other branches of psychology or science.

Here is my quick bullet point breakdown of what makes a science, inspired by the work of Cooper, Heron and Heward (2007).

The Characteristics of a Science

-The goal of science is to gain a “thorough understanding of the phenomena under study”, to identify what is true.

-In order to create the empirical knowledge base of any chosen field, there are three different types of scientific investigations that can be used.  These are; description, prediction and control.

  • Description

Through the systematic observation of events, facts can be examined and potential hypotheses for future research can be identified.

Example:  White (1975) conducted observations of the way teachers interacted with their students in classrooms. Their main discovery was that teachers delivered more statements of disapproval to students than praise in Year 4 classes onwards. This study sparked countless others which investigated this finding in more detail and how to encourage teachers to initiate more positive interactions.

  • Prediction

When two variables co-occur together, research can identify this as a correlational relationship. This information can be used to make predictions. The presence of one event can be used to assess the likelihood that another event will also occur.

Example:  Does the number of hours spent studying (Variable 1) predict the percentage of Psychology exam grades (Variable 2) in A-level students? The graph below illustrates a correlation between these two variables.

  • Control

Highly controlled experiments are conducted to demonstrate cause and effect: manipulating one variable (the independent variable) will consistently cause a measurable change in another variable (the dependent variable). It is also important that the change in the dependent variable was not caused any other factor which happened to co-occur with the independent variable (known as a confounding variable, as it confounds the results of the study!).

Example: To conduct an experiment to determine whether studying for longer periods of time results in a higher percentage exam grade in A-level psychology students, the researcher would need to recruit a large number of students (i.e. 100) from different colleges and split them into various conditions. They would manipulate how much studying the students in each condition would be allowed to do (independent variable), then they would measure how well they performed on an exam created by the researchers (dependent variable). Their exam results would then be compared to analyse which condition achieved the highest exam grades. 

A Living, Breathing Science..

Scientists work through the different stages of empirical investigation until they can demonstrate control. Showing a causal relationship is the gold standard of scientific practice. When you can reliably state that one variable is the causal agent for another variables occurrence, this is when your research becomes more respected and closer to uncovering the truth about the phenomena under study.

Interestingly, it is worth bearing in mind that even when countless studies demonstrate the same cause and effect relationship, this is also, paradoxically, a type of correlation!

Cooper, Heron and Heward (2007) said it best “In fact, all we ever really know is that two events are related or “co-related” in some way. To say that one “causes” another is to say that one is solely the result of the other. To know this, it is necessary to know that no other factors are playing a contributing role. This is virtually impossible to know because it requires identifying all possible such factors and then showing that they are not relevant (Johnston & Pennypacker, 1993a, p.240).” p24.

This is the reason why psychology researchers never usually state that a study has ‘proved’ their theory.  We can only really demonstrate that our hypothesis was correct within our particular study, or a series of studies, at that specific time. In the future, we might develop new technology or research methods which may confound the current evidence base within our field. Psychology is a living, breathing science!


Without scientific study, the world would be full of ignorance and misguided judgements. 

It is my view that psychology is a science and I hope that this article has helped to convince you of that! We use the scientific methods of investigation (description, prediction and control) to gain a thorough and true understanding of the causes of behaviour. Our knowledge base changes, as our research advances. This characteristic is true of all scientific fields.

And if you are still cynical of psychology and its scientific merit? Then look out for the second part in this series, where I will discuss the scientific attitudes that psychology upholds in much of its research.



Notes: *Luckily, the electric shocks were not really administered to the other person behind a screen, but the participants in Milgram’s study were made to believe that the electric shocks that they delivered were indeed very real.


Cooper, J. O., Heron, T. E., & Heward, W. L. (2007). Applied Behavior Analysis, 2nd ed. Upper Saddle River, N.J.: Pearson Prentice Hall.

Milgram, S. (1963). Behavioral Study of obedience. The Journal of abnormal and social psychology67(4), 371.

Header image via Pexels.

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