What is a Science?

When we look at different approaches and applications to psychology, we can evaluate both their content (concepts, theories and models) and methodologies (research methods and key studies) in terms of how scientific they are. Elements of study that make something scientific are:

  • Objectivity – there must be no individual subjectivity (due to interpretation) affecting study
  • Reductionism – studying complex areas using one sole focal aspect
  • Operationalisation – making variables being investigated quantifiable and measurable
  • Other elements include: reliability, credibility, control, empirical data and hypothesis testing

Hypothetico-deductive model

Karl Popper was concerned about showing whether a psychological theory was scientific, and whether it was true. He proposed that the development of a scientific theory is as follows:

  • Science involves proposing explanations (hypotheses) based on a scientific theory
  • This is tested against experience, by observation and experimentation (empirical testing as based on experiences with the world – data are gathered by the senses)
  • Scientific knowledge is built up based on a means of testing and amending the hypothesis, and the cycle repeats
  • This is the hypothetico-deductive model of reasoning
  • If not proven, a theory may be rejected rather than amended

This model can be applied to psychology, as this cycle of developing theories and testing them to accept, reject or amend
the theories, is what psychology is all about. This can be noticed in observations and experiments. If it’s a psychological
hypothesis you are testing by experimentation, you are trying to build knowledge in a scientific way you cannot do with a
case study.


Popper acknowledged that psychological hypotheses, as with any in the sciences, make specific predictions based on theories from an area of study, and that any hypothesis being tested runs the risk of being proven wrong. It must be possible to show that they are wrong, and this is called falsification. Popper therefore believed that the difference between sciences and non-sciences was not the ability to verify, but the ability to falsify. Scientists will take a hypothesis which they wish to test, and use experimentation to try and disprove the theories, and by this means try to reject the hypotheses in question. Therefore, studies which do not disprove the theories mean that those theories must be tentatively accepted – even if we cannot prove they will not be falsified in the future.
This is where psychology could be argued to be less scientific: scientists try to disprove their theories in order for accepting of hypotheses to be more valid, whereas psychologists always true to prove hypotheses. Psychology is said never to try and falsify theories, as a psychologist is unlikely to try and disprove their own theory.

The paradigm

Philosopher of science, Thomas Kuhn, suggested that science cycles, with new sets of beliefs about science replacing older sets of beliefs. The sets of beliefs, known as the paradigm, are the underpinning of assumptions of a scientific approach. The paradigm is used to explain and predict the world, but also defines the way in which research is conducted. When a set of theories are improved through new evidence, and methods change, there is a paradigm shift. When we consider applying the paradigm approach to science, it is difficult to apply to psychology. This is because it is hard to suggest that psychology has just one paradigm – it is not just one area of knowledge, and there is never only one way of looking at an issue with psychology. So from Kuhn’s perspective, it cannot be said that psychology is a science: different approaches to psychology explain things very differently.


Science uses reductionism – it is hard to operationalise variables that are too broad, so a specific part of the whole complex nature may be studied in particular. Holism involves looking at the ‘whole’ situation, as this is sometimes more relevant than just studying each individuals component (holists take the view that the ‘whole’ adds up to more than each ‘part’ added together). In psychology, a reductionist view is used almost exclusively in experimentation, isolating behaviours to be tested – the variables. The independent variable and dependent variables need to be able to be separated and measured in order to test the hypothesis, and psychology generally achieves this. The only exception is in case studies. Most case studies use holism, as they gather qualitative and in-depth data which cover more than one aspect of behaviour. This means they cannot be transferred to correlations, etc. Holistic studies are not scientific, but since the vast majority of psychological study and experimentation uses reductionism, it can be argued from this sense that psychology is a science.

Scientific subject matter

Psychology covers a number of areas which are seen to be scientific. The ‘sciences’ are areas of study where scientific methods are used. Generally there is a tendency to call specific subjects “scientific” because they involve elements of
biology, chemistry or physics, but by this definition of a science, there are other areas which are also sciences, such as environmental sciences and geological sciences. The areas which are seen as ‘scientific’ by the standard definition of science include studying genes, hormones and drug therapies. However, by this approach to science we need to take into account that it also covers areas within different approaches which are far less scientific, because the concepts are not easily measurable. Most of the psychodynamic approach suffers this weakness, as Freud was subjective and used no scientific methods at all; the same goes for psychoanalysis as a therapy. Psychologists appreciate this and when evaluating work will criticise studies on being unscientific.

Psychological Approaches and Science

Social approach and science
  • Field experiments such as Hofling et al. (1966) and laboratory experiments such as Tajfel (1970,71) use controlled methods of study which offer reductionism and operationalisation of variables
  • The social approach aims for controlled and objective studies
  • However, methodologies using interviews or questionnaires may introduce subjectivity as they require interpretation
  • Ethnographic studies looking for differences across cultures, such as Meeus and Raaijmakers (1986) tend to generate qualitative data which are not likely to be scientific
Cognitive approach and science
  • Field experiments such as Godden and Baddeley (1975) and laboratory experiments such as Craik and Tulving (1975) use controlled methods of study which offer reductionism and operationalisation of variables
  • Other research methods include brain scanning and neuroscience studies, which are scientific
  • The approach studies processing in the brain, which has access to measurable biological information
  • Cognitive psychology looks at concepts which are hard to measure (such as levels of processing, cue-dependency)
  • Case studies are used (such as Clive Wearing) which are hard to generalise to form a scientific body of knowledge
Psychodynamic approach and science
  • There was no original scientific experimentation by Freud, but later studies have used such methodologies, such as Adams et al. (1996) who looked into homophobia
  • Case studies were used a lot by Freud to base the psychodynamic concepts on, which are not generalisable or scientific, as they require subjective interpretation and biased samples, and collect ambiguous qualitative data
  • Concepts are not scientifically or objectively measurable
Biological approach and science
  • Laboratory experiments which use scientific techniques, such as brain scanning – such as De Bellis et al. (2001)
  • Careful controls as you are testing a hypothesis
  • Studies are seen generally as measurable, credible and reliable, and the content is regarded as scientific
  • Although content is scientific, case studies such as Money (1975) are not
Learning approach and science
  • Laboratory experiments often involving animal studies are used, such as Skinner (1935), Seligman (1967) and Pavlov (1927)
  • There is reductionism as behaviour is reduced to parts to make it more measurable (such as Seligman using his dogs to test his learned helplessness theory)
  • The approach aims to discover the general laws of behaviour and development, which is scientific
  • However, it is hard to generalise from animal studies as the findings may not apply to humans – making them less scientific
  • Further, ignoring cognition and emotions ignores human functioning


Go Further

Bad Science