Monday, May 24, 2004


Scout, at And Then..., links to an interesting article in yesterday's Guardian:
In a high-profile launch this week, Education Secretary Charles Clarke will announce the findings which disclose that young children carry a daily expectation of being kidnapped by a stranger, sexually abused by a paedophile or becoming a victim of terrorism.

'We are not just failing to give children the opportunities to explore the real world,' said Di McNeish, director of policy and research at Barnardo's, which carried out the study with the Green Alliance, 'but are actively dissuading them by making them over-anxious about their external environment.

The survey of more than 1,000 children aged 10 and 11 reveals that the choice to remain indoors is being made because of an increasingly unrealistic assessment by children and their parents of the risks of the outside world.
When I was a kid, I thought juvenile diabetes was very common. Any time I felt unusually thirsty, I wondered if I might be coming down with diabetes. I was really worried about it. What was my problem? My father was a pediatrician who specialized in endocrinology. He treated most of the diabetic kids in town, and he talked a lot about his diabetic patients - especially the ones who wound up in the hospital. I didn't know that he saw more diabetics than other doctors did, and I didn't know that he talked about sick patients more than he talked about well-baby checkups, so I concluded that my risk of developing diabetes was sky-high. I was a victim of the availability heuristic.

Heuristics are mental rules of thumb, cognitive shortcuts which help us make sense of the overwhelming amounts of data bombarding us every second of the day. Mostly, heuristics are a good tradeoff - what you lose in accuracy, you gain in reaction speed and ease of processing. "Things that leap out at me are dangerous," for example, is a good general heuristic even though someday Ed McMahon might leap out at you with the Publisher's Clearinghouse sweepstakes check.

The availability heuristic is the tendency to perceive events which easily come to mind as more common or more likely. For example: are there more words in the English language that start with R, or more words that have R as the third letter? Most people try to come up with an answer by thinking of some words, and conclude that words that start with R are more common when in fact, they're just easier to bring to mind.

The availability heuristic is what leads us to be overly influenced by big news stories. The more people hear about something, the more common they tend to think it is. For example, not many people are aware that in the era of Columbine and other well-publicized school shootings, the overall rate of lethal school violence in the U.S. actually decreased.

As a species, we're not very good at estimating risks - particularly uncommon risks. We overestimate the danger of spectacular, showy, newsworthy, or intensely frightening threats (such as kidnapping, or terrorist attacks) and underestimate the danger of commonplace, everyday threats (such as car accidents). More parents worry that their daughter will be given poisoned Halloween candy than worry that she'll date a boy who hits her, and yet the second threat is common and the first almost unheard-of.

So claims that today's children are "overprotected" are both true and false: we overprotect our children from some dramatic or well-publicized risks, while failing to protect them sufficiently from other risks which receive less attention. It's not surprising that the kids in the Guardian study aren't any good at making accurate risk estimates either.

(Test your ability to avoid the availability heuristic here. See heuristics gone drastically, drastically wrong here.)