In one recent national survey of teenagers who had been in relationships, 29 percent reported experiencing sexual or physical abuse or receiving threats of physical violence from partners. About 10 percent of students in grades nine to 12 consistently say they've been physically hurt on purpose by a dating partner during the past year, according to the ongoing Centers for Disease Control and Prevention (CDC) youth risk surveys. Kids who witness violence between their parents are at higher-than-average risk to be the abusers--and the abused. Perhaps surprisingly, girls and boys are equally likely to turn violent with dating partners. But girls suffer more severe injuries. Teens who use alcohol or drugs and have trouble managing anger are especially likely to strike out against boyfriends or girlfriends. But dating violence can affect anyone at any time. Nobody is exempt. With awareness growing on many campuses, 11 states since 2007 have passed laws mandating that schools teach teens about partner abuse or at least draw greater attention to the problem. The new laws and increasing availability of curricula have prompted a surge in prevention programs over the past few years, mostly at middle schools and for the youngest high school students. Dating abuse can shatter a teen's self-esteem. Victims are also more prone to binge drinking, drug use and eating disorders. Harmful effects even reverberate into adulthood: Teens entangled in violent dating relationships are more likely than others to be involved in violent activities later on.