Protected Characteristic

A personal attribute that is protected from discrimination under equality legislation. Under the UK Equality Act 2010, the nine protected characteristics are: age, disability, gender reassignment, marriage and civil partnership, pregnancy and maternity, race, religion or belief, sex, and sexual orientation. Similar protections exist in other jurisdictions under different names. Disability is unique among protected characteristics because the law permits asymmetric treatment (favoring disabled people is lawful) and requires affirmative reasonable adjustments. In AI fairness research, protected characteristics are central to measuring and mitigating algorithmic bias.