In Brief

SPARE THE ROD Preschool kids who receive harsh physical punishments from parents tend to display excessive aggression as schoolchildren, says a study at Lehigh University in Pennsylvania. Researchers find that these youngsters end up feeling humiliated, frustrated by their unmet needs and unworthy of care. Later they mimic their parents' model of violence to cope with social situations.

TUNING OUT Aggressive behavior can actually be "unlearned," a Stanford University study finds, if children limit their use of TV, videos and electronic games. After a six-month experiment, researchers report that children who reduced their TV time to seven hours a week and stuck to less-violent videos and games were half as likely as their peers to engage in bellicose playground behavior like taunting and teasing. The most combative kids at the start of the study showed the most behavioral improvement by the end.

FRIENDLY ADVICE The top factor in teens' decisions to drink or smoke is whether they have friends who do, a National Institutes of Health study suggests. Researchers find that teens tend to behave like their five closest friends do, and girls are more likely than boys to give in to pressure to drink. However, parental involvement counts: kids whose moms and dads talk and listen to them regularly are less likely to smoke or drink.