UK: NATSAL-3 and a bit of NISVS 2010

NATSAL-3 is short for National Survey of Sexual Attitudes and Lifestyles 2010-2012. Currently six papers on this survey is published in The Lancet.

Among the things measured by this survey was non-volitional sex and one of the Lancet papers is on this subject:

Lifetime prevalence, associated factors, and circumstances of non-volitional sex in women and men in Britain: findings from the third National Survey of Sexual Attitudes and Lifestyles (Natsal-3)

First off I have to commend that both CSEW and NATSAL give access to the complete questionnaires – in contrast to CDC for example. This makes it much easier to obtain a more comprehensive understanding of the findings reported in the paper itself.


Sample was 15,162 people aged 16-74 living in Britain.

The interview process were taken in two steps (as described in this document on methodology), first some general questions and some screening questions using CAPI (face-to-face) and then depening on the answers to the screening questions the respondent were asked to answer some more detailed questons using CASI (where the respondent fill out a questionaire on a computer in privacy).

There were some things I wondered about with the screening used (PDF page 129):

Routed in if:
  • they reported heterosexual sex aged 13+ and/or
  • they reported any sexual experience in expscale or
  • they refused to answer expscale
Not routed in if:
  • no sex aged 13+ and
  • no sexual experience

(here the authors were a bit sloppy, the second to last line should read “no heterosexual sex aged 13+”)

They use having had heterosexual intercourse as one of the possible requirements for being routed into the self-completion questions. It just struck me as weird this focus on heterosexual intercourse rather than just intercourse. Would this affect the number of homosexual respondents being routed to the self-completion questions where they ask about non-consensual sex? Probably not since another screening questions ask about the respondents sexual experience:

Sexual experience is any kind of contact with another person that you felt was sexual (it could be just kissing or touching, or intercourse or any other form of sex). I have had some sexual experience…
  1. (R) Only with (females/males) (or a (female/male)), never with a (male/female)
  2. (Q) More often with (females/males), and at least once with a (male/female)
  3. (T) About equally often with (females/males) and with (males/females)
  4. (B) More often with (males/females), and at least once with a (female/male)
  5. (Z) Only with (males/females) (or a (male/female)), never with a (female/male)
  6. (W) I have never had any sexual experience with anyone at all
  7. Refused

(The CAPI software will strike out the appropriate male/female part depending on the reported gender of the respondent.)

If the respondent answer anything other than 6 (W) I have never had any sexual experience with anyone at all they will be routed on to the CASI part so in theory any respondents who have experienced same-sex intercourse after the age of 13 should be included.

One question I am left with is whether any espondents who were sexually abused before they were 13 and who hasn’t had heterosexual intercourse after the age of 13 will recognize and classify their abuse as “any kind of contact with another person that [they] felt was sexual”? If they for some reasons don’t classify their sexual abuse as a “sexual experience” they will not be routed to the CASI part where questions about non-volitional sex are asked. I’ll point out that it desn’t matter either way because those respondents are filtered out by the questions in the CASI part only asking about non-volitional sex happening after the age of 13.

For instance is the term non-volitional not used in the questions to the respondents. It is a term used when summarising and reporting the findings. In this document containing the questionaire the section with questions about non-volitional sex is titled “Non-consensual sex”, the questions themselves use neither terms:

The next question is about your experience of sex when you might not have been willing.
Since the age of 13, has anyone tried to make you have sex with them, against your will?
1. “Yes”
2. “No”
3. Don’t know

If the respondent answered Yes to the question above the question below were asked.

“And since the age of 13, has anyone actually made you have sex with them, against your will?
1. “Yes”
2. “No”
3. Don’t know

“Having sex” is defined as including vaginal, oral and anal sexual intercourse.

I think it is very possible that some respondents who have been raped would answer no to the question whether anyone has ever tried to make them have sex. Is an actual rape also an attempted rape in the respondents mind?
There is a real potential for underreporting here – especially since this is in CASI and there is no possibility for a interviewer to adjust the answer if the respondent for instance answered “No, the rapist didn’t just try” to the first question about attempts.

This also mean that every respondent who reported a completed rape also had to reported an attempt. I wonder if those are subtracted from the number of attempts reported in the findings.

Another consequence of this is that this makes it easier to compare the findings of NATSAL-3 with the findings of NISVS 2010.

Also note again that any non-volitional sex experienced before the age of 13 is not included. This means that the lifetime numbers reported in the findings aren’t really lifetime numbers. There are research on childhood sexual abuse which report that younger boys could be more at risk for intercourse than younger girls (6.7% vs 5.6% (table 2))- if that is correct then this cut-off at 13 used by NATSAL-3 would skew the numbers to include fewer male victims of non-volitional sex.

The findings

Attempted non-volitional sex was reported by 19·4%  of all women and 4·7% of all men.
Half of women (50·5%) and almost a third of men (29·8%) who reported attempted non-volitional sex went on to report completed non-volitional sex,
such that completed non-volitional sex was reported by 9·8%  of women and 1·4% of men.

(confidence intervals and links to figures have been edited out by me for readability)

This reveals every 8th victim of completed rape is a man.
The ratio between women and men for attempted non-volitional sex was about (4.7%/19.4%) ~0.25 making every 5th victim of attempted non-consensual sex a man.

So how does this compare with the NISVS 2010 Report

One difference is that the questions in the NATSAL-3 report didn’t ask explicitly about victimization when the respondent were drunk, high, drugged, or passed out and unable to consent. Would that leave to an underreporting and if so could the underreporting be skewed by gender?

Yet the findings of the two surveys are almost identical:

Attempts (including completed) rape NATSAL-3 NISVS 2010
Women 19.4% 18.3%
Men 4.7% 4.8%

It would’ve been very interesting if the NATSAL-3 survey had had “last 12 months” prevalency numbers as well.

A hat-tip to Ally Fogg who made me aware of this survey in this blog post.

10 thoughts on “UK: NATSAL-3 and a bit of NISVS 2010

  1. Hey, tamen. Thank you for going through this. The very similar result to the NISVS is replication which should be the gold standard of science. I am much more confident in those numbers now compared to a few weeks ago since they clahed with my initial intuitions.

    I have to speak a genuine praise: In the nline gender debates you seem to be one of the most levelheaded people out there and I can only tell you that your rigorous treatment of primary sources is an important contribution to the whole discourse.

  2. This is great, and fascinating. I somehow assumed that the NATSAL results weren’t lifetime but as you’ve demonstrated it seems to be pretty much in line with other surveys that ask men aswell. Ally Fogg’s comment, “It also highlights why estimates of lifetime risks of a crime like rape – the incidence of which is not evenly spread over a lifetime – are fundamentally flawed. Claims like “1 in 5 women will be raped” “1 in 10 women will be raped” or any such calculation are fundamentally flawed,” raised some interesting questions for me, what was the age that men reported having these experiences, is this something that happens more today than it did in the past ( and does that explain the difference in lifetime vs 12 month rates for men ) or does it rise and fall in line with other crimes.

  3. Sasori:

    First I’ll note that the age cohorts given are the age of the respondents at the time the survey was done, not their age at the time of the incident. Which means that we can’t really say anything about how incidents are spread out over a lifetime. Not the least because one respondents may have experienced several incidents spanning over a number of years.

    Your related questions whether this [rape] is something that happens more today than it did in the past is not answerable by this survey – or any lifetime number surveys I know of.

    If there even exists one asking the respondents to list all incident and place them on a timeline everything I’ve read about self-reporting accuracy would suggest that we’d see telescoping (dates are skewed towards now) and underreporting (the respondents don’t recall all incidents) .

    If a survey like the NISVS were to be repeated every second year or so over a sufficient number of years one could build a timeserie of the “last 12 months” prevalency numbers and one would get a pretty good picture of trends.

    That said, here is the breakdown for attempted non-volitional sex experienced by men by age-cohorts at the time of the interview according to table 2 in the paper:

    Age group at interview Attempted non-volitional sex
    16-24 3.7%
    25-34 4.4%
    35-44 4.2%
    45-54 5.9%
    55-64 5.8%
    65-74 4.1%

  4. Tamen: At risk of making you burst a blood vessel, I’m sure there are many other people like me who don’t always comment but who enjoy reading the material you have here!

    It’s a real shame NATSAL-3 only looked at lifetime prevalence. And also I find it strange that they didn’t describe specific situations like being incapacitated, physically forced, pressurised etc. Both of these choices seem like weaknesses of the research to me, although it’s good they did something at least. Another notable limitation that stands out for me is the following:

    The mean and median numbers of years (interdecile range) since the last occurrence were 22·5 and 22 years (5—40) for women, and 23·2 and 22 years (5—48) for men.

    They’re asking people about experiences they had (often while drunk or high) almost a quarter of a century ago on average.

  5. Thanks for the links Pål.

    I have read what is freely available on the Sosiologi i Dag (Sociology today) Vol 43 Nr 4 issue and I am disappointed that they keep questioning the use of gender neutral terms about domestic violence and sexual violence.

    I remember that Kjetil Rollness article from when it was originally published after the “Kønskriget” documentary was sent on television.

    As for the article in Aftenposten plugging the Sosiologi i Dag issue I find it predictably depressing that for an article titled “Sexual violence harms not only women” almost exclusively spoke about violence against women – the exception being sexual violence against children. The paragraph where there was a discussion about whether one should differentiate “mild” and “aggravated” sexual violence and how the continuum of sexual violence as a term is compatible with the feminist term sexualized violence (which earlier was defined as sexual violence against women because they are women). Many of us know how for instance researchers like the authors of NISVS 2010 Report and laws (UK’s Sexual Offences Act 2003 and the Crime Survey for England and Wales (CSEW)) either count a significant subset of male rape as a “mild” sexual violence or discounts it altogether.

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