The impact of the postponing sexual involvement curriculum among youths in California

Postponing Sexual Involvement (PSI) is a widely implemented middle school curriculum designed to delay the onset of sexual intercourse. In an evaluation of its effectiveness among seventh and eighth graders in California, 10,600 youths from schools and community-based organizations statewide were recruited and participated in randomly assigned intervention or control groups; the curriculum was implemented by either adult or youth leaders. Survey data were collected before the program was implemented, and at three months and 17 months afterward. At three months, small but statistically significant changes were found in fewer than half of the measured attitudes, behaviors and intentions related to sexual activity; at 17 months, none of these significant positive effects of the PSI program had been sustained. At neither follow-up were there significant positive changes in sexual behavior: Youths in treatment and control groups were equally likely to have become sexually active, and youths in treatment groups were not less likely than youths in control groups to report a pregnancy or a sexually transmitted infection. The evaluation suggests that PSI may be too modest in length and scope to have an impact on youths' sexual behavior.