Sample Representativeness in Psychological and Brain Science Research

Psychological and brain science explore human behavior and the human brain by studying volunteers who participate in these studies, and the generalizability of findings in these fields largely depends on the representativeness of samples. However, the representativeness of samples in psychological and neuroscience research has long been criticized. There are two main problems with current research: (1) Lack of sample information. Most studies report only the gender/sex, age, and country of the subjects, while important information such as race/ethnicity, education level, and socio-economic status of the subjects is rarely reported. Moreover, this situation has not changed significantly over time; (2) The information provided suggests that the current sample is not sufficiently representative: there are more female participants than male participants, and they are concentrated in the Western, young, and highly educated populations, while middle-aged and older people, people with lower education levels, and low-income groups are less concerned by researchers. Asian, Black/African American and Hispanic/Latino populations also receive less attention. From a national perspective, populations in Asian, African, and Latin American countries are less represented in psychological and neuroscience research. The above two major problems may be mainly due to the following reasons: convenience sampling method as the main sampling method; European and American researchers have led the research in psychological and brain science; neglect of the influence of culture and various demographic factors as a whole; researchers themselves have biases. Changing this situation will require the combined efforts of researchers, academic organisations, journal editors and funders. Improving the representativeness of samples will help to apply the scientific knowledge of psychological and brain science to a wider range of groups, thereby promoting the building of a community with a shared future for humanity.