Racism (27): Black Students Face Harsher Discipline

At least they do in U.S. schools:

Although black students made up only 18 percent of those enrolled in the schools sampled, they accounted for 35 percent of those suspended once, 46 percent of those suspended more than once and 39 percent of all expulsions … Over all, black students were three and a half times as likely to be suspended or expelled than their white peers. …

Black and Hispanic students — particularly those with disabilities — are also disproportionately subject to seclusion or restraints. Students with disabilities make up 12 percent of the student body, but 70 percent of those subject to physical restraints. Black students with disabilities constituted 21 percent of the total, but 44 percent of those with disabilities subject to mechanical restraints, like being strapped down. And while Hispanics made up 21 percent of the students without disabilities, they accounted for 42 percent of those without disabilities who were placed in seclusion. (source, source)

What are the reasons for these differences in discipline rates? I guess it can only be one of two things: either black students are particularly unruly, or many teachers are prejudiced. Racists will obviously adopt the former explanation: in their minds, racial discrepancies in discipline are not evidence of racism but rather evidence of the inferiority of the black race. Let’s assume for a moment that teachers do not treat black pupils unjustly and that those pupils deserve their treatment on account of their behavior: we should probably not assume this, but even if we do this would not necessarily be evidence of racial inferiority. There may still be background discrimination. Why do black kids behave the way they do – if they do indeed behave in ways that deserve harsher discipline? Could it not be because of racism elsewhere in society?

More posts in this series are here.

Racism (15): Does the Stigma of “Acting White” Explain the Racial Achievement Gap in Education in the U.S.?

In many areas of life, different racial groups in the U.S. achieve unequal results. African-Americans earn less, are more likely to be in prison, are more often ill etc. So it’s no surprise that there’s an achievement gap in education as well.

At nine months old, there are no detectable cognitive differences between black and white babies. Differences emerge as early as age two, and by the time black children enter kindergarten they are lagging whites by 0.64 standard deviations in math and 0.40 in reading. On every subject at every grade level, there are large and important achievement differences between blacks and whites that continue to grow as children progress through school. Even accounting for a host of background factors, the achievement gap remains large and statistically significant. (source)

While the education gap seems to be closing, it remains wide. It’s likely that other multicultural societies face the same kind of problem. Racists have an obvious explanation: racial inferiority! Anti-racists have an equally obvious but more convincing explanation: racists! But apart from the effects of lingering racist discrimination there’s also a more interesting cause of the education gap: the stigma of “acting white“, causing minority students to suffer from the negative prejudices of their ethnic peers. Roland G. Fryer has looked at this, and found that it can explain a lot.

“Acting white” is a kind of negative peer pressure. Black peer communities impose costs on those members who are perceived to be “acting white” (or are trying to “act white”). The criticism of “acting white” and the costs imposed on those who are believed to “act white” lead to the avoidance of behavior that is seen as the traditional prerogative of whites. The avoided behavior can be quite harmless, for instance wearing clothes of a particular brand that is believed to be typical of whites, or giving your children certain “white” names. But the avoided behavior can also undermine people’s education, for example when people are discouraged to use standard English, to read books or to achieve high grades. (And even the seemingly harmless habit of giving your kids “black” names can result in harm. It’s known, for instance, the employers regularly discriminate people with “black” names while processing job applications).

The individuals exposed to all these kinds of negative peer pressure have a disincentive to invest in their education. They deliberately underachieve in order to avoid social sanctions. Naturally, the degree of the disincentive depends on the nature and the level of the costs imposed: those costs can be the threat of rejection, ridicule etc. Different people will suffer different costs and will perceive the gravity of the costs differently, but as long as there is a perceived trade-off between acceptance and authenticity on the one hand and achievement on the other, there will also be an achievement gap.

Fryer measures the impact of the stigma using social popularity, number of friends and friendship patterns plotted against school grades. His results clearly show an inverse relationship between grades and popularity for non-whites.

Not surprisingly, the effect of “acting white” is more severe in integrated schools than in predominantly black schools. The reason is the higher level of competition between communities and the perceived threats between groups:

In an achievement-based society where two groups, for historical reasons, achieve at noticeably different levels, the group with lower achievement levels is at risk of losing its most successful members, especially in situations where successful individuals have opportunities to establish contacts with outsiders. Over the long run, the group faces the danger that its most successful members will no longer identify with its interests, and group identity will itself erode. To forestall such erosion, groups may try to reinforce their identity by penalizing members for differentiating themselves from the group. The penalties are likely to increase whenever the threats to group cohesion intensify. (source)

This explanation of the causes of the “acting white” stigma, based on the desire of groups to preserve their identity in the face of external threats to their internal coherence, is more convincing that the two major alternative explanations:

• Blacks have developed a culture of investing themselves in alternative pursuits rather than in education because historically academic achievement was the prerogative of whites. This explanation reeks of historical determinism.
• Blacks have developed a culture of “victimology” and deliberately engage in cultural sabotage. This explanation can be perceived as racist.

“Acting white” explains a lot but surely not everything. It’s likely that the racial poverty and income gaps also contribute to the education gap, as do patterns in family structure, incarceration rates of black fathers, school quality etc. Stereotype threat can also play a part. As well as some good ol’ racism, of course.

Lies, Damned Lies, and Statistics (17): The Correlation-Causation Problem and Omitted Variable Bias

Suppose we see from Department of Defense data that male U.S. soldiers are more likely to be killed in action than female soldiers. Or, more precisely, the percentage of male soldiers killed in action is larger than the percentage of female soldiers. So there is a correlation between the gender of soldiers and the likelihood of being killed in action.

One could – and one often does – conclude from such a finding that there is a causation of some kind: the gender of soldiers increases the chances of being killed in action. Again more precisely: one can conclude that some aspects of gender – e.g. a male propensity for risk taking – leads to higher mortality.

However, it’s here that the Omitted Variable Bias pops up. The real cause of the discrepancy between male and female combat mortality may not be gender or a gender related thing, but a third element, an “omitted variable” which doesn’t show up in the correlation. In our fictional example, it may be the type of deployment: it may be that male soldiers are more commonly deployed in dangerous combat operations, whereas female soldiers may be more active in support operations away from the front-line.

OK, time for a real example. It has to do with home-schooling. In the U.S., many parents decide to keep their children away from school and teach them at home. For different reasons: ideological ones, reasons that have to do with their children’s special needs etc. The reasons are not important here. What is important is that many people think that home-schooled children are somehow less well educated (parents, after all, aren’t trained teachers). However, proponents of home-schooling point to a study that found that these children score above average in tests. However, this is a correlation, not necessarily a causal link. It doesn’t prove that home-schooling is superior to traditional schooling. Parents who teach their children at home are, by definition, heavily involved in their children’s education. The children of such parents do above average in normal schooling as well. The omitted variable here is parents’ involvement. It’s not the fact that the children are schooled at home that explains their above average scores. It’s the type of parents. Instead of comparing home-schooled children to all other children, one should compare them to children from similar families in the traditional system.

Greg Mankiw believes he has found another example of Omitted Variable Bias in the data plotting test scores for U.S. students against their family income:

Kids from higher income families get higher average SAT scores. Of course! But so what? This fact tells us nothing about the causal impact of income on test scores. … This graph is a good example of omitted variable bias … The key omitted variable here is parents’ IQ. Smart parents make more money and pass those good genes on to their offspring. Suppose we were to graph average SAT scores by the number of bathrooms a student has in his or her family home. That curve would also likely slope upward. (After all, people with more money buy larger homes with more bathrooms.) But it would be a mistake to conclude that installing an extra toilet raises yours kids’ SAT scores. … It would be interesting to see the above graph reproduced for adopted children only. I bet that the curve would be a lot flatter. Greg Mankiw (source)

Meaning that adopted children, who usually don’t receive their genes from their new families, have equal test scores, no matter if they have been adopted by rich or poor families. Meaning in turn that the wealth of the family in which you are raised doesn’t influence your education level, test scores or intelligence.

However, in his typical hurry to discard all possible negative effects of poverty, Mankiw may have gone a bit too fast. While it’s not impossible that the correlation is fully explained by differences in parental IQ, other evidence points elsewhere. I’m always suspicious of theories that take one cause, exclude every other type of explanation and end up with a fully deterministic system, especially if the one cause that is selected is DNA. Life is more complex than that. Regarding this particular matter, education levels are to some extent determined by parental income (university enrollment is determined both by test scores and by parental income, even to the extent that people from high income families but with average test scores, are slightly more likely to enroll in university than people from poor families but with high test scores).

What Mankiw did, in trying to avoid the Omitted Variable Bias, was in fact another type of bias, one which we could call the Singular Variable Bias: assuming that a phenomenon has a singular cause.