A few possible definitions of "discrimination"

Summary

This page collects a few random thoughts on possible meanings of "racism", "sexism", and similar terms. I'm not an expert on this topic, and there are many further nuances to concepts like racism and sexism, including their historical contexts.

Introduction

Words like "racism" and "sexism" permeate popular culture and political discourse. The terms are usually deployed as if their definitions are self-evident or universally understood. However, I think these words can mean many different things, and the generic terms are best considered as clusters of related ideas, similar to concepts like "virtue" or "athletics".

"Pure" discrimination

One classic interpretation of racism is disliking someone merely because of the color of her skin. Given the complexity of human psychology, it's tough to tease apart when discrimination is "merely" based on skin color vs. based on, for example, beliefs that another group of people is actually different in some more substantive way. We could define "pure" racism as racism that's entirely based on the physical/bodily components of race, not based on any beliefs about psychological or behavioral traits correlated with race.

One type of "pure" discrimination that's not socially taboo and is often praised is favoritism of people in one's family over strangers. It also tends to be acceptable to favor those in one's country over foreigners. It's interesting to ponder why these types of discrimination aren't regarded with the same outrage as discrimination based on certain demographic traits. One possible reason is that the worst forms of racism involve active hostility to those of other races, while favoring one's family and country typically involve at worst indifference to the outgroup (unless the outgroup immigrates into one's country). Another possible reason is that it's psychologically very difficult for many people not to privilege their families, while it's somewhat easier to not privilege one's racial group.

One person on /r/DebateAltRight makes an explicit analogy between racism and favoring one's family: "I will always be on the side of white people because I consider them my extended family, I have a connection to them. I don't have that sort of connection to non-whites, so I don't care about them."

In my case, I've sometimes been criticized by my friends for not showing enough favoritism to my family members. However, like most people, I'm still very selfish in terms of putting more effort into my own wellbeing than the wellbeing of others, far beyond what's justifiable from a utilitarian perspective. Selfishness is presumably the most psychologically unshakeable form of pure discrimination of all.

Stereotypes

I would presume that in many cases, dislike of the outgroup results from a messy combination of "pure", intrinsic animus combined with belief in negative stereotypes.

Stereotypes can be misguided in at least two ways:

1. The generalization is not true, even on average.
2. The generalization is true on average but is applied too aggressively in presuming the traits of an individual (this is the "ecological fallacy").

When the "effect size" of a generalization is smaller, it's more likely that the ecological fallacy will in fact be fallacious. For example, if I make the generalization that "25-year-old men are stronger than 8-year-old boys" (as measured by, say, who would win an arm-wrestling contest), this will sometimes be wrong in particular cases, but because the effect size is so substantial, generalizing from group differences to individual differences in this case will usually give the right answer. In contrast, the generalization that "women are more interested in psychology than men" will be wrong when making many individual comparisons of men and women.

Discrimination with predictive models

We can think of individual people as points in a high-dimensional space of attributes, such as "height", "bone density", "IQ", "knowledge of Russian literature", "interest in basketball", and so on. Almost all of these variables are correlated with one another to some degree, which means that almost all variables could be used in a statistical model to predict other variables, with varying degrees of accuracy. There's probably a nonzero correlation between, say, the trait "wears velcro shoes" and the trait "enjoys British comedies", even if the size of the correlation is small and its sign (positive vs. negative) is non-obvious. If racism is defined merely as "believing there's probably some nonzero correlation between race and some other attributes of people within some population", then basically all statisticians are racist. Also sexist, ageist, and so on.

Another interpretation of racism could be the belief that these observed correlations are partly genetic rather than purely environmental. The non-racist stance would be that correlations between traits do exist, but they're purely the result of "nurture" factors like socioeconomic inequalities, rather than "nature" factors. However, in theory, I presume that basically any gene would have some nonzero (though perhaps minuscule) correlation with basically any trait you might wish to measure across a large population after holding "nurture" factors constant, because any (potentially very minor) differences in micro-level biology (genes) should lead to (potentially very minor) differences in macro-level biology (phenotypes).

Maybe everyone agrees that genes have some correlation with other traits, but racism/sexism would be when you think these correlations are large and highly explanatory of social outcomes. Merriam-Webster's first definition of "racism" begins: "a belief that race is the primary determinant of human traits and capacities". Note that this refers to a belief about facts rather than values. Also, this definition doesn't seem to extrapolate well to defining "ageism" or "speciesism" because age and species are in fact strong determinants of an organism's traits and capacities. However, Merriam-Webster's first definition also includes a normative component: "that racial differences produce an inherent superiority of a particular race".

I agree with Galef (2017):

Human psychology appears to be such that if you acknowledge that a mean skill level is even slightly higher in group A than group B, we waaaay over-update, and act as if all individual A’s are higher-skill than all B’s. So perhaps talking about the possible existence of group differences is just too damaging to be worth it.

With this framing, racism and sexism can be seen as similar to the way in which people may over-update on other kinds of information. For example, if a study reports that religious people are slightly happier on average, someone might overestimate the effect size of this result and then assume he has to become religious in order to be happy. Studies reporting small average differences between two populations (such as religious vs. non-religious people) can be fun if taken as amusing entertainment but can be harmful if interpreted too seriously.

A charitable interpretation of those who advise to "never discuss the possibility of biological gender differences" is that they believe that nixing the whole conversation is the most effective way to prevent people from vastly exaggerating modest scientific findings. It can be tempting to explain away observed inequalities by appealing to inherent traits of a group rather than looking at what other factors might have caused the situation and what approaches could be tried to address it.

A specific instance of over-updating on small or non-existent effect sizes is stereotype threat: "If negative stereotypes are present regarding a specific group, group members are likely to become anxious about their performance, which may hinder their ability to perform at their maximum level."

One might also believe that in some cases, even if a variable is a strong predictor, it shouldn't be used, for reasons of fairness. For example, while almost all terrorists are men, one might say that as a matter of government policy, men shouldn't be stopped for checks by airport security more than women, because that would create a feeling of unfairness on the part of the non-terrorist men. Of course, screening may still be done based on other traits. So policies against discrimination isolate specific predictor variables that are off limits, even though other predictor variables can be used. Perhaps this is justified if certain predictor variables are particularly invidious.

In some contexts, such as charging young men more for car insurance, there doesn't seem to be much outrage over policies of sexism and ageism. I support charging men more for car insurance based on the statistics, even though I'm a man myself. (I also probably favor stopping men more than women at airports.)

Equal consideration of interests

Another possible interpretation of discrimination is that it refers to violating the principle of equal consideration of interests, as Peter Singer explains in chapter 2 of Practical Ethics. If I recall correctly, Singer notes that even if there were differences in certain traits between races and sexes on average, those differences wouldn't change the core of equality, which is to equally count the wellbeing of different people regardless of race or sex.

For example, suppose we're considering a decision that affects one woman, Alice, and one man, Bob. Alice has a utility function u_A, and Bob has a utility function u_B. The aggregate utility U of Alice and Bob, using some weights w_A and w_B, is

I interpret the principle of equal consideration of interests as saying that we should set w_A = w_B. For example, if both weights are set to 1, then

Making decisions to optimize this aggregate utility function would not be sexist.

I like this approach, but it runs up against the problem that there's no clear or unique way to make interpersonal comparisons of utility. For example, suppose an observer, Charles, is assessing an action that will affect Alice and Bob. If the action is taken, Charles thinks, Alice's utility will decrease by 5, while Bob's utility will increase by only 3. Thus, relative to Charles's estimates, the change in aggregate utility from taking the action would be

Since ΔU is negative, Charles opposes the action. However, Charles sees that Doug supports the action. Charles accuses Doug of being sexist because Doug seemingly gives more weight to Bob's interests than to Alice's. Perhaps Charles thinks that Doug is calculating

But Doug can say that, no, he's not giving Bob's utility function more weight than Alice's; it's just that Bob's interests are stronger than Charles thinks they are. In particular, Doug says his calculation is

Since the weights on Δu_A and Δu_B are equal, this calculation is apparently non-sexist.

Lack of objectivity regarding interpersonal comparisons of utility is particularly acute when considering non-human animals, because there are wider brain differences in this case. What looks like speciesism to one person may look to another person like correctly recognizing that non-human animals have weaker interests than humans because non-humans have less cognitive complexity.