Do your kids seem to be getting a shorter attention span? There could be some scientific evidence of that.

The older generation always complains about kids. But researchers who study the effects of television actually have data to suggest that young people today don't pay attention in the way their parents do.

Annie Lang and her colleagues at Indiana University have done a series of studies in which college-age people and middle-aged people were shown a string of t.v. and movie clips. In one trial, they showed images which changed at a fast rate -- over eleven shots every thirty seconds.

Other trials had images that changed at slower rates -- five to six changes, or zero to three changes, every thirty seconds. People from all three groups were quizzed after watching the videos to see how much they could remember.

The results differed depending on a couple of factors, such as how arousing the images themselves were. But in general they found that young people have a much harder time than adults in paying attention to, and remembering, slower-moving material.

It's not necessarily laziness. They try, but slow material is hard for them. And adults fared worse at remembering fast-moving material.