When considering human behaviour, bias is a tendency to treat one individual or group in a different way from others. In the context of gender bias, psychological research or theory may offer a view that does not justifiably represent the experience and behaviour of men or women (usually women)
Male-centred; when 'normal' behaviour is judged according to a male standard (meaning that female behaviour is often judged to be 'abnormal' or 'deficient' by comparison)
Psychological theories that suggest there are real and enduring differences between men and women. These may enhance or undervalue members of either sex, but typically undervalue females
Psychologists, like the rest of us, possess beliefs and values that have been influenced by the social and historical context within which they live. Thus, bias may be an inevitable aspect of the research process.
Alpha bias within psychological research is that which exaggerates or overestimates differences between the sexes. Such differences are typically presented as real and enduring; fixed and inevitable.
The central premise of sociobiological theory is that sexual promiscuity in males is genetically determined whilst females who engage in the same behaviour are regarded as going against their 'nature' - an exaggeration of the difference between the sexes (alpha bias).
Beta bias ignores, minimises or underestimates differences between men and women. This often occurs when female participants are not included as part of the research process and then it is assumed that research findings apply equally to both sexes.
If our understanding of what counts as 'normal' behaviour is being drawn from research that involves all-male samples, then any behaviour that deviates from this standard is likely to be judged as 'abnormal', 'inferior' or 'deficient' by comparison.
Gender-biased research may create misleading assumptions about female behaviour, fail to challenge negative stereotypes and validate discriminatory practices. It may provide a scientific 'justification' to deny women opportunities within the workplace or in wider society.
A lack of women appointed at senior research level means that female concerns may not be reflected in the research questions asked. Male researchers are more likely to have their work published and studies which find evidence of gender differences are more likely to appear in journal articles than those that do not.
The laboratory experiment - seen as the cornerstone of 'scientific' enquiry in psychology - may further disadvantage women. Female participants are placed in an inequitable relationship with a (usually male) researcher who has the power to label them unreasonable, irrational and unable to complete complex tasks.
Many modern researchers are beginning to recognise the effect their own values and assumptions have on the nature of their work. Such reflexivity is an important development in psychology and may lead to greater awareness of the role of personal biases in shaping research in the future.