Psychological research has shown three major effects of seeing violence on television:

h Children may become less sensitive to the pain and suffering of others

h Children may be more fearful of the world around them

h Children may be more likely to behave in aggressive or harmful ways toward others.

Children who watch a lot of TV are less aroused by violent scenes than are those who only watch a little; in other words, they're less bothered by violence in general, and less likely to see anything wrong with it. One example: in several studies, those who watched a violent program instead of a nonviolent one were slower to intervene or to call for help when, a little later, they saw younger children fighting or playing destructively.

Studies by George Gerbner, Ph.D., at the University of Pennsylvania, have shown that children's TV shows contain about 20 violent acts each hour and also that children who watch a lot of television are more likely to think that the world is a mean and dangerous place.

Children often behave differently after they've been watching violent programs on TV. In one study done at Pennsylvania State University, about 100 preschool children were observed both before and after watching television; some watched cartoons that had a lot of aggressive and violent acts in them, and others watched shows that didn't have any kind of violence. The researchers noticed real differences between the kids who watched the violent shows and those who watched nonviolent ones.

'Children who watch the violent shows, even 'just funny' cartoons, were more likely to hit out at their playmates, argue, disobey class rules, leave tasks unfinished, and were less willing to wait for things than those who watched the nonviolent programs,' says Aletha Huston, Ph.D., now at the University of Kansas.

. Television can be a powerful influence in developing value systems and shaping behavior. Unfortunately, much of today's television programming is violent. Hundreds of studies of the effects of TV violence on children and teenagers have found that children may:

h Become "immune" to the horror of violence;

h Gradually accept violence as a way to solve problems;

h Imitate the violence they observe on television; and

h Identify with certain characters, victims and/or victimizers:

Extensive viewing of television violence by children causes greater aggressiveness. Sometimes, watching a single violent program can increase aggressiveness. Children who view shows in which violence is very realistic, frequently repeated or unpunished, are more likely to imitate what they see. The impact of TV violence may be immediately evident in the child's behavior or may surface years later, and young people can even be affected when the family atmosphere shows no tendency toward violence.

This does not mean that violence on television is the only source for aggressive or violent behavior, but it is a significant contributor.