“The average rapist rapes about six times.”
Then he mentioned this statistic — and stepped into a hornet’s nest of fierce debate among specialists on sexual assault.
This is one of those easy-to-remember statistics that emerge out of academic research. But whether it is accurate is another question.
The White House did not respond to a request for a source for Biden’s comment. But Biden most probably was referring to a 2002 study, “Repeat Rape and Multiple Offending Among Undetected Rapists,” principally by David Lisak, then at the University of Massachusetts at Boston. (Lisak is vice chairman of 1in6, a group that helps men who have had abusive sexual experiences.)
The report said it drew on four samples of a total of 1,882 men between the ages of 18 and 71, who answered questionnaires, in exchange for a small payment, after they encountered researchers while walking across a college campus between 1991 and 1998. The researchers found 120 men “whose self-reported acts met legal definitions of rape or attempted rape, but who were never prosecuted by criminal justice authorities.” Of these men, 76 were identified as “repeat rapists” based on their survey responses. “These repeat rapists each committed an average of six rapes and/or attempted rapes and an average of 14 interpersonally violent acts,” the report said.
While Biden spoke generally about all rapists, the report purported to be about college rapists (though it is not known if all of the men surveyed were actually college students, and the average age of the respondents was 26.5 years old). Note also that the statistic is for both rapes and attempted rapes, not just rapes.
The statistic is still in circulation, even though it is based on data as much as 30 years old, but it has been controversial. Lisak and his research methods have been under attack for many years.
Linda LeFauve, associate vice president for planning and institutional research at Davidson College in North Carolina, has written at length about what she views as the flaws in Lisak’s paper. She has charged he pooled data from surveys of uncertain provenance, the participants were not necessarily college students and it’s unclear how many people were subject to follow-up interviews.
“There is no research to confirm the Lisak statistic, studies that dispute it, and more than sufficient evidence that Lisak has been perpetrating a fraud,” LeFauve said. Nevertheless, she said, his research was embraced during the Obama administration when the White House organized a task force on campus sexual assault. And she said — even though she voted for both Barack Obama and Biden — she was dismayed to see it resurrected under Biden.
Mary P. Koss, a regents’ professor in the College of Public Health at the University of Arizona, noted that she testified before Biden’s committee when the Violence Against Women Act was under consideration. “I am very saddened that advisers to the president have misinformed him,” she said. “The figure he uses is actually not able to be fact-checked because it provides an ‘average,’ which would most appropriately come from a national sample that doesn’t exist in the scientific literature.”
As for college students, she said she published the only national study of rape perpetration by college students — a survey of more than 6,000 students published in 1988 — and “the average number of rapes by men who self-disclosed acts that met a legal definition of rape was 2.6.”
In 2015, Koss contributed to a report published in the journal JAMA Pediatrics that was a direct assault on Lisak’s research. “Though a small group of men perpetrated rape across multiple college years, they constituted a significant minority of those who committed college rape and did not compose the group at highest risk of perpetrating rape when entering college,” the study said.
The study, whose lead author was Kevin Swartout of Georgia State University, “was highly contested, re-peer-reviewed three times by JAMA at Lisak’s complaints, was deemed sound and never withdrawn,” Koss said. “Lisak’s critique of the study was also peer-reviewed and rejected for publication. This paper is scientifically complex but at highest levels of peer review discredits Lisak’s empirical work and the claims he extrapolates from it.”
Lisak, in an exchange of emails with The Fact Checker, said “LeFauve’s quote is full of bluster but empty of facts” and dismissed the 2015 JAMA study. “Those researchers brought the number of serial offenders in their study down by redefining serial offending so that many subjects who had multiple victims were no longer counted as serial offenders,” he said.
Lisak denied he submitted a critique of the JAMA study. (Koss says she saw his comments but conceded that perhaps he did not formally submit them because it was “a losing battle.”) Lisak provided a 2017 report, written by Jim Hopper, one of his former students, and posted on Hopper’s website. Hopper said he adjusted the JAMA data set to the definitions used in Lisak’s 2002 report, coming up with similar results. “Research suggests that about two‐thirds of college rapists are repeat offenders, who account for the great majority of rapes (over 90%), and about one‐fourth of college rapists admit to committing rapes over multiple years of college,” Hopper wrote.
“The Internet is not a valid source of peer-reviewed information,” Koss said. “He has his self-serving opinion, but JAMA did not support it.”
Lisak also pointed to two subsequent studies that he said reported numbers close to his, one from 2009 (6.5 rapes per serial rapist among Navy recruits) and one from 2019 (five rapes per serial rapist among college students).
- “Reports of Rape Reperpetration by Newly Enlisted Male Navy Personnel.” (2009). This study surveyed 1,146 enlisted male Navy personnel and found that 13 percent (144) engaged in actions that met the definition of attempted or completed rape. Of them, 71 percent engaged in more than one attempt, with an average rate of almost 6.5 incidents. This is clearly a study of serial rapists, not necessarily “average” rapists.
- “Is Campus Rape Primarily a Serial or One-Time Problem? Evidence From a Multicampus Study.” (2019). This study relied on data from the Core Alcohol and Other Drug Survey of 12,624 college men at 49 community and four-year colleges and concluded that serial rapists were the cause of most campus rapes. The lead author, John D. Foubert of Union University, acknowledged that the survey (in question 21) does not actually ask about rape but offers a vaguer question — whether the person had “taken advantage of another sexually” because of alcohol or drug use. “You are right to question the item we used, though. It is the major limitation of our study,” he told The Fact Checker. “In my view, it would be better called ‘sexual assault’ than rape.”
“As a researcher, I see many limitations to these studies,” Lisak said. “However, given the research we have, it is clear that 1) serial sex offending is an extremely important issue; 2) the available data tells us that serial offenders account for the majority of sex offenses being committed (which is also true of drug dealers, burglars, bank robbers, etc.).”
Lisak summed up: “Six is as good a number to cite as any, and probably better than most.”
“At present, I don’t know of other research that would confirm the finding,” said Foubert, who is dean of the College of Education at Union. “I will say that in my experience as a college administrator, anecdotally, it did seem to me that offenders were often multiple offenders.” He added: “I’m thankful that President Biden is at least citing a study that is peer-reviewed. Many politicians don’t understand the difference between a peer-reviewed study and a Cosmo article.”
“There are many different opinions on Lisak’s article,” Foubert added. “I am less critical of it than some, indeed, but more critical than many practitioners.”
New research may further undermine this statistic. Swartout said he had recently completed a national survey of 697 male four-year college graduates based on their sexually violent behavior while in college. “I found that the average college man who commits rape assaults 1.48 victims. To help contextualize this a little more, 81.7 percent of the men in the study who reported committing rape reported assaulting one victim,” he said. “Overall, 10.2 percent of the overall sample reported perpetrating rape while they were an undergraduate student.” He said the study was being finalized for peer review and would be submitted to JAMA Pediatrics.
Moreover, a 2020 study of DNA samples from rape kits collected in Michigan, with Rebecca Campbell of Michigan State University as lead author, found that of the men who were associated with multiple sexual assault cases, the vast majority (about 70 percent) of suspected perpetrators were linked to two cases. “We did document a small group of offenders who were linked to 3+ assaults, but that was not the typical pattern,” Campbell said.
Koss said Biden should withdraw his statement. “The president’s statement, sadly, should be corrected to advise policymakers on the basis of sound scientific evidence,” she said.
LeFauve said these sorts of statistics are appealing because they fit neatly in existing narratives. “No one wants to be on the side of the bad guys,” she said. “And the minute you question rape statistics — the misleading claims about false reports is its own rabbit hole — you’re on the wrong side.”
The Pinocchio Test
Sexual assault of women is an important issue, and Biden has long been a leader in pressing for laws to combat it. But now that Biden has the presidential megaphone, he has a responsibility to use statistics that are widely accepted and not controversial.
Perhaps he remembered this statistic from the Obama administration’s work on campus sexual assault, but that was some time ago. Even then, Lisak’s findings were under fire from other academicians.
The Lisak paper was published almost two decades ago and primarily focused on campus sexual assault, not the “average rapist,” as Biden put it. Moreover, the statistics come from a relatively small sample of men who were self-selected as they walked across a college campus. It was not based on a nationwide sample.
Obviously, The Fact Checker cannot litigate the debate between Lisak and his critics. But the White House should be aware of the dispute and be more cautious about validating a statistic that may or may not be correct. Otherwise, Biden may be perpetuating misinformation.
Ordinarily, given the academic dispute, we’d consider this a Two-Pinocchio claim. But because the president turned a study about campus rape into a statistic about the average rapist, he earns Three Pinocchios.
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