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Rapes Assisted By Drugs Or Alcohol Are All Too Common

Bill Cosby has been accused of sexual assault by more than 40 women, many of whom say he drugged them before the assault. In newly released court document from a 2005 civil case that Cosby settled out of court, he admitted that he deliberately obtained Quaaludes (a sedative) to give to women he wanted to have sex with. (He refused to comment on whether he gave the drugs to women surreptitiously.) Although some of the women have filed civil suits against Cosby, he has not been charged with a crime. But the actions he’s been accused of are not uncommon in cases of sexual assault. Studies suggest that a large share of rapists assault people who are incapacitated by drugs or alcohol, though relatively few administer the drugs themselves.

A November 2005 report from the U.S. Department of Justice gave drug tests to 144 women who had reported being the victims of sexual assault and who had come to clinics for an exam. Sixty-two percent of the women had drugs in their system, and 5 percent tested positive specifically for substances that are considered date-rape drugs. However, those numbers don’t quite reveal what percentage of assault victims were drugged. One date-rape drug (clonazepam) was found only in people to whom it had been prescribed. Another date-rape drug (flunitrazepam, also known as Rohypnol or roofies) was found in several women both at their initial visit and at follow-ups, suggesting that they were taking it regularly, possibly as a sedative or anti-anxiety drug, and had not necessarily been given it by their assailant.

To gain a clear sense of what drugs might have been given surreptitiously to a woman who had been assaulted, the DOJ researchers compared the drugs in a victim’s system to what she reported taking herself, and to the drugs in her system at a follow-up visit. Based on this data, the researchers estimated that 4.2 percent of the women reporting assault had been surreptitiously drugged.

However, there is a much more common way that drugs are used in rape: when victims take the drugs intentionally and then a rapist takes advantage of their incapacitation. The DOJ estimated that more than a third of the women in the study (35.4 percent) had been the victims of a drug-facilitated sexual assault when these cases were included.

Women’s self-reporting of surreptitious druggings produces a higher estimate than the one the DOJ arrived at clinically. Twenty-four percent of women in the DOJ study said they suspected that they had been given a drug, and an additional 12 percent were unsure. Some of these women may have been correct in their suspicion but came to the clinic after the drug had left their system. Others may have been incapacitated, but because of drugs they took themselves, rather than a drug their assailant slipped them.

The Washington Post and the Kaiser Family Foundation conducted a survey of 1,053 current and recent college students from January to March of 2015 and asked respondents about their experiences with sexual assault. Fourteen percent of women and 4 percent of men reported that they had been sexually assaulted while incapacitated by drugs or alcohol, or while asleep. This was the most common kind of assault experienced by both sexes (9 percent of women and 1 percent of men reported assault by physical force).

Nine percent of women who had been sexually assaulted or experienced unwanted sexual contact suspected that they had been drugged immediately beforehand. Sixty-two percent of the women surveyed had been drinking before the assault or unwanted contact. That matches the results of study after study finding that alcohol is the most common substance found in drug-facilitated sexual assaults.

The self-reports of rapists align with those of rape victims. David Lisak, a clinical psychologist, surveyed 1,882 male college students between 1991 and 1998 and found 120 whose descriptions of their sexual activities met the criteria for rape or attempted rape, but who had not been charged. Eighty-one percent of these undetected rapists reported that they had had sex with women who were incapacitated because of drugs or alcohol. (The study did not ask if the men had deliberately caused that incapacitation or if they had preyed on women who were already incapacitated.) Assaulting incapacitated women was, by far, the most common method of sexual assault — far fewer rapists said they had used threats or overt force for sexual intercourse (9 percent). Serial rapists and one-time rapists were equally likely to assault women who were incapacitated because of drugs or alcohol.

Although clinical assessments of rape victims and the self-reports of victims and rapists suggest that drug-facilitated sexual assault makes up a large share of sexual assaults, surveys of the population at large suggest that these kinds of assaults are more likely to be treated skeptically. The Washington Post asked college students whether a number of scenarios met the criteria for sexual assault. Ninety-six percent of students thought that sexual activity occurring when one participant was incapacitated was assault. But students were less sure about incidents in which both participants were under the influence of alcohol or drugs. Only 21 percent said these scenarios represented sexual assault, 19 percent were unsure, and 59 percent said these encounters were not assault.

When students were asked about the sentiments on their campus, 16 percent said it was “very common” that their classmates believed a woman who was sexually assaulted while drunk was somewhat responsible for what happened. An additional 37 percent said that this attitude was “somewhat common” at their school.

Overall, a lot of sexual assaults involve drug- or alcohol-induced incapacitation, but relatively few are the result of a rapist drugging a victim directly, as Cosby is accused of doing. In the more common case, where a rapist takes advantage of a victim’s intoxication, students are less willing to consider this kind of drug-facilitated sexual assault as rape.

Leah Libresco is a former news writer for FiveThirtyEight.