Wednesday, April 21, 2004

The Short Attention Span Generation?

Over in the comments section of this thread, Daniel Green has been arguing for the existence of a decline in attention span over time in both children and adults, presumably the result of the rise of television. This would be fascinating if it were true, particularly in light of persistent worldwide gains in IQ during the last century. But Daniel wouldn't cite any evidence other than his own dissatisfaction with his former students, so I had to go do his research for him.

Here's what I found, after an exhaustive search of psychological and medical research databases: nothing. No evidence of cohort effects, secular trends, or historical trends in attention, attention span, or sustained attention. Not for children, and not for adults. There is evidence (free registration required) that recent generations of elderly adults have better cognitive abilities, including memory, than previous generations did at the same age. That's about it for historical trends in attention.

So younger generations don't have shorter attention spans, but what about That Devil TV? Just a couple of weeks ago, a study came out in the journal Pediatrics which claimed that TV watching in toddlerhood contributes to attentional problems in the early elementary years. It got a lot of media coverage. So I went to the library and read the article, and sheesh. Let me just say that, although Pediatrics is a great journal for medical research, there's no way that this study would ever have been published in a top-ranked psychology journal.

Here's the deal. Researchers asked mothers of 1 and 3-year-old children how much TV their children watched. When children were 7, their mothers were asked to rate whether the child "has difficulty concentrating," "is easily confused," "is impulsive," "has trouble with obsessions," and "is restless." Mothers were allowed to qualify their answers as "very true" vs. "somewhat true," but the researchers ignored the distinction and scored even "somewhat true" answers as "yes." They did not have experts examine the children. They did not have the children complete any actual tests of attentional ability. They did not collect evidence of whether the supposed memory problems were clinically significant - that is, whether they affected children's performance at school, at play, or at home. They did not make any efforts to measure the amount of TV the children actually watched.

Here's what else they didn't do. Although they controlled for a lot of variables which might have influenced attention problems, they didn't control for family socioeconomic status (SES). That's a huge omission, because lower-income children are more likely to have attention problems and are also more likely to watch TV. Controlling for SES is standard in most developmental research, so it's odd that they left it out. (They did control for maternal years of education, but that's a pretty weak measure of SES.)

All this is not to say that I think it's healthy to plop a toddler down in front of the TV all day, every day. TV takes up time that toddlers should be using for activities with a higher developmental payoff. But the methodology of this study is so bad that the results simply can't be trusted, and the huge media blitz means that millions of parents have just been given one more thing to feel guilty about.