The foiled underpants bomber, Umar Farouk Abdulmutallab, raises anew the question of how to spot a terrorist. Clear hindsight obscures how hard a task this is. After the 2001 attacks on New York City and Washington, D.C., the German authorities analyzed data for some 8 million potential terrorists living in Germany by a variety of categories and whittled that list down to 1689 individuals, each of whom they hauled in for an interview. Not one turned out to be a threat, according to the social scientists Diego Gambetta and Steffen Hertog in a New Scientist comment.

Gambetta and Hertog mention this and other failed attempts to find good classifiers for profiling terrorist by way of arguing that engineers are three to four times as likely as other graduates to be affiliated with Islamic terrorist groups since 1970. Perhaps, they argue, university subjects provide a key to better classifiers.

Slate has recently picked up their thesis, but the Slate article is less concerned with the data than with Gambetta and Hertog’s speculation on root causes:

We reckon that something else is going on, something at the individual level, that is, relating to cognitive traits. According to polling data, engineering professors in the US are seven times as likely to be right-wing and religious as other academics, and similar biases apply to students. In 16 other countries we investigated, engineers seem to be no more right-wing or religious than the rest of the population, but the number of engineers combining both traits is unusually high. A lot of piecemeal evidence suggests that characteristics such as greater intolerance of ambiguity, a belief that society can be made to work like clockwork, and dislike of democratic politics which involves compromise, are more common among engineers.

I found the last line about compromise very peculiar, since engineering as a profession is essentially concerned with compromising between price and performance. I am not quarreling with the basic picture here: we could surely tell a story about Hank the vegan engineer that was just as confounding as the one told about Linda the feminist bank teller.

Rather, my point is that ‘trained engineer’ and ‘practicing engineer’ might be a worthwhile distinction in exploring engineering studies as a classifier. I’d also add that, in so far as engineering students can be a bit singleminded, increasing the number and variety of optimization problems in the curriculum that include social or economic parameters might not be a bad idea.