Over one-third of men report perpetrating sexual assault when hooked up to a fake lie detector

Across studies, approximately 15-20% of women report that, since adolescence, they have experienced one or more nonconsensual sexual acts perpetrated by a man through use of incapacitation, threats of physical harm, or physical force; researchers often label these acts, which are illegal in most states, as sexual assault. An even larger percentage of women report that they have experienced nonconsensual sexual acts perpetrated by a man through use of verbal pressure or manipulation; researchers often label these acts as sexual coercion, and although they are not illegal in most states, they might be categorized as unethical and are often upsetting to the women who experience them. Thus, a fairly large proportion of women have been victims of men’s sexual aggression.

Fig. 1. Percentage of men endorsing behaviors consistent with sexual coercion and sexual assault as a function of condition.

Seemingly paradoxically, most research finds that a very small proportion of men self-report having ever engaged in nonconsensual sexual acts against a woman. This victim-perpetrator prevalence discrepancy is often explained by a “serial predator” hypothesis, which proposes that a very small proportion of men are responsible for a large number of sexual assaults. This explanation is, arguably, comforting, as it suggests that, if the small group of repeat offenders can be incarcerated, women will be safe from rape. Unfortunately, there is another potential explanation for the victim-perpetrator prevalence discrepancy: In research, men may underreport the types of behaviors that would qualify as sexual coercion or sexual assault because those behaviors are socially undesirable.

How can we evaluate whether men are intentionally underreporting nonconsensual sexual behaviors on self-report measures? Luckily, in the 1970s, social psychologists developed the Bogus Pipeline (BPL) procedure as a laboratory tool to increase honesty in self-reporting. In the BPL procedure, participants are led to believe that they are being monitored by a device—resembling a lie detector—that can determine their truthfulness.

In our study, we randomly assigned 93 young, heterosexual men to either a BPL condition (n = 58), in which they were hooked up to a fake lie detector while completing self-report measures, or a Standard Testing condition (n = 35), in which they completed measures without being hooked up to a device. In both conditions, men completed the most widely used self-report measure of sexual aggression history. The measure is behaviorally specific, meaning that it asks about specific sexual acts (i.e., oral, anal, or vaginal sex obtained through verbal pressure or manipulation, incapacitation, threats, or force) and does not explicitly use the terms “sexual assault” or “sexual coercion.”

We found no statistically significant difference in men’s likelihood of reporting sexually coercive behaviors in the BPL (41.4%) versus the Standard Testing (22.9%) condition despite a trend in that direction. However, men’s odds of reporting one or more behaviors that would legally qualify as sexual assault were 6.5 times higher in the BPL (37.9%) than in the Standard Testing condition (8.6%) (Fig. 1).

The sample size for this study was small, and results should be considered preliminary. Nevertheless, these findings have potentially important implications. These results suggest that men tend to underreport their use of illegal sexual assault behavior. Given this, rates of sexual assault perpetration may be substantially higher than has been suggested by prior self-report studies. Our findings stand in contrast to the serial predator hypothesis and suggest that the societal problem of sexual assault is unlikely to be solved by simply detecting and incarcerating a few deviant predators; instead, broader cultural change is likely needed.

Zoë D. Peterson
University of Missouri-St. Louis, USA



Use of a Bogus Pipeline to Detect Men’s Underreporting of Sexually Aggressive Behavior.
Strang E, Peterson ZD
J Interpers Violence. 2016 Dec 4


Leave a Reply