In Taiwan, on-campus sexual assault remains a key concern that influences physical and mental health, gender equality, and human rights. However, few domestic studies have explored the sexual assault–related experiences of male college students. This study focused on the prevalence, patterns, and seriality of forced sexual intercourse among male college students in Taiwan. Our findings may guide relevant investigations in the future. Koss et al. (1987) surveyed sexual assault–related experiences among male college students in the United States. Approximately 10.2% of all respondents indicated engaging in sexual contact, with 7.2% reporting sexual coercion, 3.3% reporting attempted rape, and 4.4% admitting to rape. The cumulative percentage of these various forms of sexual assault was 25.1%. After 30 years, Koss et al. (2022) conducted a follow-up study, which revealed that the proportion of male college students reporting attempted rape or rape increased to 12.7%, exceeding the proportion in the previous survey (7.7%). This finding suggests a trend toward increasing prevalence of forced sexual intercourse among male college students in the United States. In 2014, Huang surveyed a representative sample of male college students and found that the prevalence rates of forced sexual intercourse realized through verbal pressure, misunderstandings in communication, violence, and exploitation of the victim’s unconscious state (due to alcohol or drug use) were 17.9%, 11.6%, 11.6%, and 7.3%, respectively. Nonetheless, ambiguities in defining “sexual behavior” and the dated nature of evidence necessitate further investigations into the prevalence of forced sexual intercourse among male college students. Understanding crime patterns is essential for predicting and preventing criminal activity. Although official statistics offer insights into the time, place, region, season, age group, gender, occupation, and educational level related to various crimes, they primarily provide static population data. Consequently, limited dynamic and in-depth data are available for analysis. Thus, private surveys must be conducted to overcome data limitations. This study was conducted to investigate sexual assault victims’ gender; relationships between offenders and victims; and offenders’ age at first offense, crime planning, emotional state during the crime, involvement in other violent acts, and alcohol consumption before the event. Lisak and Miller (2002) analyzed the seriality of sexual offenses among male college students in the United States. Of the students surveyed, 6.4% reported engaging in forced sexual intercourse. Notably, among those who admitted to such behavior, 63.3% were repeat offenders, averaging 5.8 incidents each. The repeat offenders were responsible for 90.89% of the total 483 self-reported incidents. The researchers concluded that male college students who engage in forced sexual intercourse tended to be serial offenders. However, given the controversial nature of this topic, further investigations are needed to substantiate whether male college students involved in forced sexual intercourse generally exhibit serial offending behaviors. In the present study, data were collected using an anonymous self-report questionnaire, a method well known for its reliability and validity in measuring individuals’ self-reported experiences of sexual assault. Participants were systematically selected to represent male college students in Taiwan, informed about the inclusion of sexual assault–related questions, and assured that their responses would not be linked to any identifiable data or used for legal proceedings. The study protocol was approved by our research ethics committee (permit number: 10905ES050). Notably, the later stages of this study coincided with the COVID-19 pandemic, during which educational institutes adopted distance learning measures, which delayed the survey in some departments. Consequently, the final sample size was 1,015, which was smaller than the originally planned sample size (1,500).

The proportion of male college students reporting forced sexual intercourse ranged from 3.3% to 5.5%; this range was lower than that reported by a decade-old study (Huang, 2014). Several factors may explain this discrepancy. The two studies differ in terms of methodologies; the previous study used a scale format for the survey, whereas the present study used a mandatory single question for each type across four categories. This difference might have introduced considerable measurement errors. Furthermore, the ratio of public to private university students in the previous study was 28.2:71.8, which was close to the ratio reported by the Ministry of Education. By contrast, this ratio was 36:64 in the present study, indicated an elevated representation of public university students. The relatively high proportion of public university students in the present study may explain the reduced proportion of male students reporting forced sexual intercourse because public university students are less likely to engage in forced sexual intercourse than private university students. However, when these proportions are converted into actual numbers, the data remain substantial. Data from the Ministry of Education show that 587,164 male college students in the 2021 academic year. Thus, the estimated number of male college students who have engaged in forced sexual intercourse ranges from 19,376 to 32,294. If repeated incidents by the same individuals are considered, the incidence rate becomes particularly concerning. Most incidents of forced sexual intercourse involved female victims, with only seven involving male victims. Regarding victim–offender relationships, the results consistently indicated that the majority of the offenders were acquainted with the victims, mostly though current or former romantic relationships. This finding challenges the prevalent stereotype that “rape is usually committed by strangers.” A substantial number of offenders first committed such crimes between the ages of 18 and 22 years, suggesting that the relative freedom and reduced supervision (because of living away from home) in college life facilitate certain sexual behaviors. Approximately 60% of the offenders reported finding the experience pleasant, whereas others found it to be unpleasant. This discrepancy highlights the diverse attitudes and reactions among perpetrators. Furthermore, the planning of forced sexual intercourse varied among the offenders. Some of them reported no prior contemplation, suggesting that situational factors often influence such behaviors. Thus, some offenders may deliberately commit such sexual offenses, whereas

others may engage in such behavior impulsively. This finding indicates the heterogeneous nature of perpetrators and challenges the oversimplified notion that rape results solely from spontaneous sexual impulses. Regarding alcohol consumption, drinking before dates emerged as a predictor of forced sexual intercourse. We found a significant, although not exceedingly strong, correlation between forced sexual intercourse and other violent behaviors. This finding suggests that the motives behind forced sexual intercourse can extend beyond mere violence to include elements of power and sexual control. Regarding seriality, each perpetrator was involved in nine incidents on average, suggesting that some perpetrators were serial offenders responsible for most of the incidents. Possible explanations for this phenomenon are as follows. First, highly educated perpetrators can strategically avoid detection and punishment, which enables them to commit repeated offenses without facing consequences. Second, perpetrators with social advantages, such as high education, often have increased opportunities for interactions, which may enable them to commit repeated offenses. Finally, the perceived success or pleasure derived from the act may lead to addiction-like behavior, prompting repeated offenses. To prevent forced sexual intercourse among male college students, we recommend the universal implementation of sexual assault prevention programs on campuses, introduction of public awareness campaigns linking alcohol consumption to the likelihood of committing sexual assaults, and adoption of bystander intervention strategies. These measures may help reduce incidents of sexual assault and create a safe college environment.