Conservative estimates of sexual assault prevalence suggest that 25 percent of American women have experienced sexual assault, including rape. Approximately one-half of those cases involve alcohol consumption by the perpetrator, victim, or both. Alcohol contributes to sexual assault through multiple pathways, often exacerbating existing risk factors. Beliefs about alcohol's effects on sexual and aggressive behavior, stereotypes about drinking women, and alcohol's effects on cognitive and motor skills contribute to alcohol-involved sexual assault. Despite advances in researchers' understanding of the relationships between alcohol consumption and sexual assault, many questions still need to be addressed in future studies. KEY WORDS: sexual offense; assault and battery; aggressive behavior; AODR (alcohol or other drug [AOD] related) behavioral problem; AODR violence; AODR interpersonal and societal problems; personality trait related to social interaction; AOD expectancies; victim of abuse; social context; alcoh ol cue
Sexual assault' of adolescent and adult women has been called a silent epidemic, because it occurs at high rates yet is rarely reported to the authorities (Koss 1988). Several reasons contribute to the underreporting of sexual assault cases. Many victims do not tell others about the assault, because they fear that they will not be believed or will be derogated, which, according to research findings, is a valid concern (Abbey et al. 1996b). Other victims may not realize that they have actually experienced legally defined rape or sexual assault, because the incident does not fit the prototypic scenario of "stranger rape." For example, in a study by Abbey and colleagues (1996b), a woman wrote, "For years I believed it was my fault for being too drunk. I never called it 'rape' until much more recently, even though [repeatedly told him 'no'."
This article summarizes current knowledge about alcohol's role in sexual assault and discusses questions that remain to be answered by future research. Alcohol's contribution to sexual assault cannot be discussed without also describing the general characteristics of sexual assault; thus, this article alternates between providing information about sexual assault in general and contrasting this information with findings regarding alcohol-involved sexual assaults.
THE PREVALENCE OF SEXUAL ASSAULT AND ALCOHOLINVOLVED SEXUAL ASSAULT
The prevalence of sexual assault, both involving and not involving alcohol use, cannot be accurately determined, because it is usually unreported. Estimates of sexual assault prevalence have been based on a variety of sources, including police reports, national random samples of crime victims, interviews with incarcerated rapists, interviews with victims who seek hospital treatment, general population surveys of women, and surveys of male and female college students (Crowell and Burgess 1996). In such studies, the estimates' adequacy varies with the sources of information used. Most researchers agree that the most reliable estimates derive from studies using multi-item scales--that is, measures containing several questions describing behaviors which constitute sexual assault in simple, nonlegal language (Koss 1988).
Based on such measures, conservative estimates suggest that at least 25 percent of American women have been sexually assaulted in adolescence or adulthood and that 18 percent have been raped. Furthermore, at least 20 percent of American men report having perpetrated sexual assault and 5 percent report having committed rape (Crowell and Burgess 1996; Spitzberg 1999; Tjaden and Thoennes 2000). Due to their accessibility, college student surveys tend to employ the most thorough measures of sexual assault by including the largest number of behaviorally specific questions. These studies suggest that approximately 50 percent of college women have been sexually assaulted, and 27 percent have experienced rape or attempted rape; in contrast, 25 percent of college men have committed sexual assault, and 8 percent have committed rape or attempted rape (Crowell and Burgess 1996; Koss 1988; Spitzberg 1999). …