Categories and Biases

Hot on the heels of the "Darwin's God" extended article (hrmmph, only available via Times Select now), New York Times scores again with a great article on neuroimaging, ethics, law and punishment (here).

I was struck by the discussion of the Implicit Association Test (IAT) being used to try to tease out how racism operates psychologically, especially when combined with startle response tests. The findings show that whites shown unfamiliar black faces have higher flight-or-flight if they also show evidence of bias on the IAT. The bias disappears for familiar black faces (MLK Jr., etc.), however. These biases work the other way, too, with African Americans showing bias towards white faces. The focus of the article is on whether that racial bias may be used in the future to change the way juries are selected, but I think it points more towards an understanding of how our brains are pre-wired to form generalizations and stereotypes as placeholders in our mental models. For white kids from the suburbs who have or have had limited contact with African Americans, for instance, there is a default xenophobia and nervous response to black faces.

An anecdote from the summer of 1998 when I was in Hiroshima, Japan: I was there for almost a month working with a professor at a local university on a machine translation project. Almost every morning at dawn, I would go running through the calm streets, down along the canals, then back to the city center to my hotel. I found very quickly that in the canal area, elders would gather for Tai Chi as the sun came up and, when a 6'2" Anglo man came running around a corner, would panic, stop in their tracks and sometimes emit little shrieks of fear. I learned to stick to the main drags and avoid those exercise zones.

Faces are very significant again, because face detection and recognition plays such a critical role, but the article does show that there is plasticity in the xenophobia--the categories aren't fixed nor is the level of response to them. If Denzel Washington doesn't elicit a strong response, it means that the category formation apparatus is biological, but the categories are learned through exposure or lack of exposure. If we are hard-wired to identify and fear groups of "others", it is also possible to displace or override that categorization mechanism by not finding any groups to assign to those categories.

The acquisition of irregular verbs during language learning has some similar properties. Irregular verbs are like run, running, ran. The past tense is not formed by the common suffix rule "add -ed" in this case, making it irregular. For children, irregular verb learning has a startling "U" shaped curve. On first exposure to an irregular verb, they just rote memorize the past tense and then use it correctly for a while. Then, over time, their performance tends to degrade as they "discover" rules like "-ed" and start to overapply them. Finally, they learn the limits of productive morphological rules and become very capable in the combination of irregular forms and regular rules. Thus, a "U" shaped curve when measuring the correct use of verbs, with initial high quality, followed by a period of incorrect usages, then finally correct use once again.

If category formation for group psychology, biases and xenophobia is largely similar to the example of verb acquisition, we should see a reduction in those biases over time with exposure to positive or non-threatening exemplars. This may be the lasting legacy of school integration and busing--more so than overcoming deficits in the capabilities of minority schools--in reducing the immediate and fearful association of skin color with otherness. Similar effects apply to the social acceptance of woman's roles and homosexuality, both of which have become gradually more accepted over time as exemplars have become increasingly common due to television.