This meta-analysis on discrimination between groups is something you might expect from sociologists, maybe from researchers in the field of (group)-psychology, but the background is in fact economic research. Do note that the researcher, Tom Lane, looked at experiments in lab-settings.
What are the results:
- In general, there is limited discrimination against the out-group (note: although it’s the case in a third of the cases)
- The strength of discrimination depends upon the type of group identity under investigation. It is stronger when identity is artificially induced in the laboratory than when the subject pool is divided by ethnicity or nationality, and higher still when participants are split into socially or geographically distinct groups.
- Third-party allocators discriminate more than decision-makers in all other roles.
- Discrimination does not significantly differ between students and non-students.
(Note: this is relevant as often students are being used for such experiments, which can make us wonder if this group is really representative for people in general).
- There is evidence for both taste-based and statistical discrimination. Tastes appear to drive the general tendency for discrimination against the out-group, but individual studies have found beliefs to affect discrimination.
Abstract of the study:
Economists are increasingly using experiments to study and measure discrimination between groups. In a meta-analysis containing 441 results from 77 studies, we find groups significantly discriminate against each other in roughly a third of cases. Discrimination varies depending upon the type of group identity being studied: it is stronger when identity is artificially induced in the laboratory than when the subject pool is divided by ethnicity or nationality, and higher still when participants are split into socially or geographically distinct groups. In gender discrimination experiments, there is significant favouritism towards the opposite gender. There is evidence for both taste-based and statistical discrimination; tastes drive the general pattern of discrimination against out-groups, but statistical beliefs are found to affect discrimination in specific instances. Relative to all other decision-making contexts, discrimination is much stronger when participants are asked to allocate payoffs between passive in-group and out-group members. Students and non-students appear to discriminate equally. We discuss possible interpretations and implications of our findings.