In The Book of Why Judea Pearl writes about a distinction between bias and discrimination from Peter Bickel, a statistician from UC Berkeley. Regarding sex bias and discrimination in the workplace, Bickel carefully distinguished between bias and discrimination in a way that I find interesting. Describing his distinction Pearl writes the following:
“He [Bickel] carefully distinguishes between two terms, that in common English, are often taken as synonyms: bias and discrimination. He defines bias as a pattern of association between a particular decision and a particular sex of applicant. Note the words pattern and association. They tell us that bias is a phenomenon on rung one of the Ladder of Causation.”
Bias, Pearl explains using Bickel’s quote, is simply an observation. There is no causal mechanism at play when dealing with bias and that is why he states that it is on rung one of the Ladder of Causation. It is simply recognizing that there is a disparity, a trend, or some sort of pattern or association between two things.
Pearl continues, “on the other hand, he defines discrimination as the exercise of decision influenced by the sex of the applicant when that is immaterial to the qualification for entry. Words like exercise of decision, or influence and immaterial are redolent of causation, even if Bickel could not bring himself to utter that word in 1975. Discrimination, unlike bias, belongs on rung two or three of the Ladder of Causation.”
Discrimination is an intentional act. There is a clear causal pathway that we can posit between the outcome we observe and the actions or behaviors of individuals. In the case that Bickel used, sex disparities in work can be directly attributed to discrimination if it can be proven that immaterial considerations were the basis for not hiring women (or maybe men) for specific work. Discrimination does not happen all on its own, it happens because of something else. Bias can exist on its own. It can be caused by discrimination, but it could be caused by larger structural factors that themselves are not actively making decisions to create a situation. Biases are results, patterns, and associations we can observe. Discrimination is deliberate behavior that generates, sustains, and reinforces biases.