NISVS Study Updates Data On Sexual Violence Prevalence

Today the Centers for Disease Control and Prevention released a study entitled"The National Intimate Partner and Sexual Violence Survey" (NISVS) that provides reliable data about many forms of sexual violence. Among its key findings:

  • “One percent, or approximately 1.3 million women, reported being raped by any perpetrator in the 12 months prior to taking the survey.”
  • “Nearly 1 in 5 women (18.3%) and 1 in 71 men (1.4%) in the United States have been raped at some time in their lives, including completed forced penetration, attempted forced penetration, or alcohol/drug facilitated completed penetration. “
  • “More than half (51.1%) of female victims of rape reported being raped by an intimate partner and 40.8% by an acquaintance…”
  • “Approximately 1 in 21 men (4.8%) reported that they were made to penetrate someone else during their lifetime…”
  • “More than 1 in 3 women (35.6%) and more than 1 in 4 men (28.5%) in the United States have experienced rape, physical violence, and/or stalking by an intimate partner in their lifetime…”

 The findings from this survey are already prompting questions about why these statistics are so dramatically different than others that have been used by the government, advocates, academics and others for years.

 You might be asked to explain why the National Crime Victimization Survey (NCVS) says fewer than 272,350 Americans were raped in 2010, while the new NISVS study says 1.3 million women were victims of rape in that same year.

 We know the reasons why and we encourage you to refresh your knowledge so that you can smoothly and effectively address these questions when they come up. If you want to study up, we suggest consulting the CounterQuo Rape Stats White Paper, as well as a Legal Momentum article co-written by Lynn Hecht Schafran that is also available in our website references section under "Statistics on Sexual Violence".

In a nutshell, the biggest difference boils down to what was asked. Two other big issues also impact results.

What was asked? Quoting from the CQ Rape Stats White Paper,  "In the past, this (NCVS) survey asked participants whether or not they were raped within the last 12 months, and definitions were only provided if the respondent asked for them." You will get dramatically different results if you ask someone "were you raped?" versus questions that ask about behavior that we define as rape or attempted rape or sexual assault (as was done in the NISVS), like "has anyone used physical force or threats to physically harm you to make you have vaginal sex? Make you perform oral sex?" Etc.   

Quoting again from our Rape Stats paper: "An example of how methodology impacts results: One researcher asked one sample of college students using the NCVS methodology and another sample using standard social science methodology and found the prevalence rates to be 11 times higher using the latter methodology compared to the NCVS."

What is the statistic about? A corollary to the issue above. Make sure you know whether the statistic refers to "rape", "rape or attempted rape", "sexual assault" etc. Does the stat refer to annual or lifetime prevalence (number of people)? Or incidence (number of incidents)? The two are different

Who was asked impacts statistics also.  Both these surveys - and many others relied on by government and advocates - were done by telephone and among non-institutionalized people. Many of the types of people we know to be particularly vulnerable to sexual violence were, therefore, not counted because they don't have a telephone (the studies are biased toward landlines) or don't speak English or Spanish. People institutionalized in prisons, nursing homes, mental health facilities, drug-treatment facilities. People who are homeless. People living in college dorms and on military bases. Immigrants from countries where sexual violence is even more normalized than it is here but who do not speak the survey's language. 

We urge you to note when discussing the statistics from NISVS that as high as these numbers are, they most likely under-estimate the true prevalence of sexual violence, as they don't include data from many vulnerable populations that other studies have shown are at high risk for sexual violence. 

 Indeed, in the very back of its report (p.84), the study authors make the point: "Even though the National Intimate Partner and Sexual Violence Survey captures a full range of victimization experiences, the estimates reported here are likely to underestimate the prevalence of sexual violence, stalking, and intimate partner violence for a number of reasons." And then they list and explain a number of reasons.

At our founding CounterQuo meeting, we agreed that it was critical that we learn to speak clearly and consistently about our statistics (and that we get more reliable statistics from methodologically sound studies). We’ve just gotten a new better study. Let's make sure we're all doing our best to avoid sloppy slinging around of statistics. Dig into study methodologies, or consult articles that explain why different studies yield different results. Only use data that come from methodologically sound research.