Which of the following best defines discrimination?

The definition of discrimination that correlates best with recognized legal and social standards is illegal, arbitrary treatment based on personal characteristics. Discrimination occurs when individuals are treated unequally or unfairly based on inherent traits such as race, gender, age, disability, or other personal attributes, rather than on their abilities, qualifications, or behaviors.

This definition highlights that discrimination not only involves unfair treatment but also emphasizes that such actions are often in violation of laws aimed at ensuring equality and protecting individual rights. By focusing on the term "arbitrary," it also indicates that the treatment is unfounded and irrational, which can further lead to a toxic environment, whether in the workplace or in wider society.

In contrast, the other options involve concepts that relate to fairness or preference based on merit rather than acknowledging the unjust nature of discrimination. Equal treatment, preference based on educational background, and priority based on job performance do not capture the essence of discrimination, as they either advocate for equity or privilege certain qualifications, which are justifiable in different contexts without the inherent bias that discrimination conveys.