Some psychologists have argued that students are the human fruit flies of psychological research (Rubenstein, 1982) . This is a reference to the extensive use of fruit flies in genetic research. As early as 1946 McNemear stated that psychology was the 'science of the behaviour of students'. Kimmel (1996) claims that 70% of social psychological research and 90% of cognitive research has used students as participants.
There are lots of reasons why students are chosen to participate in psychological research. Most psychological research takes place in Universities and Colleges. Students are easy to recruit, there are lots of them, and many Universities offer credit to students if they take part in research.
However, this may undermine the validity of a lot of psychological research. Students are not representative of the adult population, they may also be biased in terms of social class, ethnicity, and intelligence. This bias is even more acute for research conducted in the past. This means that a lot of research may be based on a biased and unrepresentative sample of the population. We may not be able to generalise the findings of this research to other people and a lot of psychological research may not tell us something fundamental and universal about human behaviour.
Some psychologists also argue that there may be ethical issues raised by the use of students in psychological research.
The link below will take you to the British Psychological magazine the 'Psychologist' where these issues are discussed in depth:
Article on students as participants in psychological experiments