Many researchers have found a link between discipline practices and behavior problem in young children. Overreactivity and laxness are two specific discipline styles that have frequently been associated with externalizing problems. Social learning theory suggests that children may learn to behave aggressively through interactions with harsh, aggressive caregivers. Patterson emphasizes the role of "coercive cycle" in the development and maintenance of problem behavior. He proposes that harsh, inconsistent parenting and non compliant, aggressive child behavior become mutually reinforcing over time, which serves to solidify a coercive interaction pattern and worsen problem behaviors. Although some studies with older children have found that harsh discipline predicts change in externalizing behavior over time , other studies examining much younger children have not. In one of the few empirical studies that has specifically examined discipline and changes in preschoolers' behavior problems, Spieker et al.(1999)found that mothers' use of negative control tactics predicted increases in problem behavior.