behavior happen inconsistently. And this physical abuse doesn't just leave kids black and blue. It also does harm to their ability to learn how to act at school and elsewhere. This can lead to the problem behaviors often seen in abused children in their later life. That's the finding of a new study. And it is the first time researchers have linked trouble learning a basic form of social skills in children to their misbehavior years later.

　　Jamie Hanson and his colleagues focused on decision-making in abused kids. Their experiments showed that physically abused kids lag behind others in learning to make choices that lead to a reward. This was true even after many trials.

　　These children stick to what they learned early in life-that rewards are rare and unpredictable, but punishment is always waiting. In situations outside their families, physically abused kids fail to adjust flexibly to new behavioral rules. Such kids never learn rules for good behavior with teachers and other children. So they end up fighting peers on the playground and acting out in class.

　　In one experiment, Hanson's team studied 41 physically abused and 40 nonabused kids. They saw a picture of a bell or a bottle. Researchers told them to choose one of those objects to earn points they could exchange for boys-researchers randomly chose whether the valuable picture would be the bell or the bottle and decided the points of each picture, but generally, the kids choosing the bell would get more points than those choosing the bottle. Kids who got enough points could choose from several cool toys in the lab. Both groups of kids chose higher-point images more often as the experiment went on. But physically abused kids lagged behind. Hanson thinks the abused kids were held back by the expectations they had picked up at home.

If the new finding holds up, Hanson says, it could lead to new ways to help such kids. For example, these kids might get training in how to tell safe apart from dangerous settings. They might also get lessons on how to control their impulses. Treatments currently just focus on helping abused children feel safe and less anxious.