Field of Science

Violence against women, religion, and the dark underbelly of statistics

In a paper which shows that women in Chile raised in a non-religious environment are less likely to be a victim of so called 'intimate partner' violence, the authors conclude that there is evidence that a moderate dose of religion actually protects against it! How can that be? And, more importantly, are they right? Let me take you on a short journey into the dark side of statistics...

'Cross-sectional' studies are ones that measure a whole bunch of stats about a group of people, and then see which ones correlate. And almost everyone knows the basic trap here - that correlation does not mean causation.

Just because A correlates with B, that doesn't mean that A causes B. It could be that B causes A, or that C causes both A and B, or any one of a myriad other arrangements!

A basic, and very common, tool used to try to strip away some of these complicating factors is multivariate analysis. The idea behind it is very straightforward.

Imagine you have a situation where you're looking at the relationship between religion (or the lack of it) and intimate partner violence (IPV). In this case, what the researchers did was take a sample of female students at university in Chile, and ask them if they had ever been a victim of violence from a spouse or boyfriend.

They also asked them how often they went to Church when they were 14, and split them into 3 groups - never attended, low/moderate attendance, and high attendance. Now, as you might expect there are some important differences between these groups.

They were concerned with a few factors, in particular, that they knew from previous research reduced the likelihood that a woman is subjected to IPV. Women who come from a big city, were better educated, or who had mothers who had jobs and earned their own money - all these factors reduce the risk.

So they used multivariate analysis to correct for any differences between the groups on these measures. What this analysis does is to tweak the data so that it is as if the three groups are the same. In other words, what come out of their model was the risk for IPV for women of different levels of family religion if all other factors are held constant.

What they found was that, working with these assumptions, moderate/low attendance significantly reduced the risk of IPV compared with the 'no religion' group. High levels of religion did not (although there was a slight trend in that direction).

So, they conclude, a little bit of religion is a good thing - but too much and you cross a boundary, where women's risk starts to increase (probably because of their diminished social status). All this is good, standard analysis, and perfectly valid.

But, and it's a big 'but' that applies to an awful lot of similar research, it does not mean that encouraging religion is the way to reduce IPV. The bugbear in the analysis has a great name: joint endogeneity.

Here's the problem: the three big factors they corrected for - urban life, education, and mother's employment - are actually all directly related to 'no religion'. They all contribute to (or result from) diverse, multicultural, emancipated worldview, and this actually undercuts religion. What's more, undercutting religion opens the flood gates to just such a world view.

Is it possible to separate them? I don't think that it is, in practice. It isn't a coincidence that these factors are better in the non-religious. It's a direct, causal effect - they have joint endogeneity. And this has important ramifications for the best way to tackle IPV in places like Chile.

To show you what I mean, you need to know that when they ran their model, using all the different factors that characterise the three difference groups (not just religion), they found that the group with the lowest predicted risk was the no religion group. And the difference was big - the risk for this group was 7 percentage points lower than for the low moderate group. They comment:

The size of this protective effect - 7 percentage points - is the same as that of never having witnessed domestic violence as a child, one of the major predictors of vulnerability to dating violence

If all three groups were the same in every way except religion, this analysis shows that a modest dose of religion is linked to less IPV risk. But in the real world, there is no way these groups are going to be the same.

You cannot, in practice, encourage religion without challenging the broad, open outlook the world that permits female enfranchisement. And this open outlook is the best and most important way to empower women and reduce their risks of being subjected to violence from their intimate partners.

And it just so happens that it also leads to atheism.


ResearchBlogging.orgLehrer, E., Lehrer, V., & Krauss, R. (2009). Religion and intimate partner violence in Chile: Macro- and micro-level influences Social Science Research, 38 (3), 635-643 DOI: 10.1016/j.ssresearch.2009.03.001

Creative Commons LicenseThis work by Tom Rees is licensed under a Creative Commons Attribution-Share Alike 2.0 UK: England & Wales License.


  1. It should be noted for your readers that several methods do exist to counteract endogeneity (instrumental variables, for example), though they can be hard to use in particular circumstances. While causality can be hard to separate out, we aren't strictly limited to just accepting joint endogeneity as it is.

  2. Yes, that's a good point. They can be separated statistically (or rather, the complex interactions can be teased out - at least in theory). It's only in terms of social engineering that they can't be separated.

  3. Tom, let me first appreciate your notes on correlation and causation and also the way you have introduced multivariate analysis.

    You concluded that a little bit of religion is a good thing - but too much and you cross a boundary, where a woman's risk starts to increase is absolutely fine.But that need not be due to social status.It could be due to selective dating.Many of these religious girls I observe have this 'need to help' and thereby end up with 'bad' guys (with ASPD).

    Why do you believe that religion is against female enfranchisement or women's empowerment?

    I believe men and women of all races are equal because God has created them equal.If I were to see achievements and physical strengths and many other variables like that there will be statistical differences, but that does not mean some one is higher or someone is lower.

    Though Christians have an objective rule book to fall back on Humanists of various cultures could be in various shades.You believe IPV is not good.A humanist in Pakistan might feel,it is his right as he is stronger and nature has given him power to do so!

    You have grown in the west which has moved from barbarism to a free world because of freedoms given by religion.You are using the same to mock it now.

    I do not know,if a small dose of religion would prevent a girl from IPV, but I feel IPV would decrease IPV if it were given to guys. No great religion in the contemporary forms encourages IPV among its members.So do we promote religious teaching to not harm the weaker sex...One might choose to.

  4. please edit and change second IPV in last paragraph to 'it'.

  5. Dear Tom,

    Imagine you were a girl and that you were walking in a silent dark night in lonely street in London.You hear some foot steps growing louder. You then notice a group of hugely built immigrants from Africa just behind you.
    Would it not comfort you to know that they are just coming out of a Bible study?
    Can you answer that truthfully?

  6. Dheeraj, it's commonly found in many cultures that religious people are more socially conservative than non-religious. Since in most cultures women have traditionally been subservient to men, that means that

    I don't think that this is necessarily the case. If, historically, women had had rights equal to men, then religious people would oppose any changes to that!

    It does have to be said, however, that all 'holy books' are creatures of the times in which they were written. And women generally do not get a good deal in them.

    I don't mock religion (at least, I don't think I do!). I try to understand it, as an outsider looking in.

  7. Peter, I don't think your adaption of Hitchen's famous challenge is particularly relevant. I don't believe there is a single case (at least, not in living memory) of a lone woman in London being attacked by men coming from a Bible study class. It's really not what I'm talking about.

  8. Tom,
    Sorry for being unclear.I should not have said London.:-)
    My point is far from Hitchen's challenge.It is in a way reverse of it.
    I totally agree when you say that a lone woman in London being attacked by men coming from a Bible study class would not take place.It could if a gang was coming from a Bar or Discotheque or a rave party but not a bible study class.
    That is the argument I place, that religion does help in protecting women.A true Christian cannot think of inflicting violence on his partner.If he does it,it goes against what he stands for.A strong atheist could do it and defend it without compunctions.Is there an objective moral law for all atheists? Obviously,there isn't.
    My point was that even though you are an atheist, in a tight situation you might be comfortable with a "bible study going" stranger than a "total" stranger.

  9. Dheeraj said:

    "You have grown in the west which has moved from barbarism to a free world because of freedoms given by religion.You are using the same to mock it now."

    This is false. Western religion opposed all of the progressive movements that led to the comparative freedom in the "Western" world.

    The U.S. declaration of independence was written by heretics, the liberal movement was motivated by atheist philosophers, the rights of the working classes were established from liberals, and the writings of the atheist Karl Marx, the womens' rights and gay rights movements have been consistently opposed by orthodox christianity.

    Religion is a reactionary force in the west which typically seeks to retard social progress.

  10. United States Declaration of Independence states "We hold these truths to be self-evident, that all men are created equal, that they are endowed by their Creator with certain unalienable Rights, that among these are Life, Liberty and the pursuit of Happiness."
    This sweeping statement of Human Rights assumes a Creator who has given those rights.

    Stalin who did not give those Human rights to his people was consistent with his atheistic philosophy.When the midevial Church (pre-reformation)oppressed the people it was against the real teachings of Christianity.

    Look at what Christianity has done to India.It was under the influence of missionaries that the system of Sati (widow burning) ceased.Christianity gave self esteem and self respect to large number of people who were traditionally oppressed in the society with denial of basic human rights.

    Rights of lower castes, women, lepers etc were voiced in India not by atheistic thinkers but by Christians in British India.The political front of British Government had to face opposition from the majority Indians for bringing in liberating laws.It was Christian missionaries who voiced their problems due to the pricking of their Christian conscience.You could read "INDIA- a grand experiment" by Vishal Mangalwadi for details.

    Religion can liberate as must as atheism could oppress.There is no official Christian government in this world which could kill atheists for holding their beliefs but there are Atheistic governments that could kill Christians for holding their beliefs.

  11. Peter, you use the term 'true christian'. If you define a 'true christian' as someone who would never be violent to their partner (among other things), then by definition they are restricted to the subset of christians who aren't. But what about all the rest?

    I'm less interested in what people tell me about how they think christians (or atheists, muslims etc) should behave, and more interested in how they actually do behave. It's an interesting question because they evidence is that they often don't behave as they are supposed to.

    For example, with reference to religious meetings, the evidence is that people who attend them are actually more likely to be hostile towards 'out-groupers' - to the point of supporting terrorists (see earlier post). That's not what we're told religion is about, but it is, in fact, what happens.

  12. Dheeraj:

    Most of the writers of the declaration believed in God, but only as the founder of the universe, not in the christian sense of an interventionist deity. It was, after all, a time before Einstein and Darwin.

    Stalin re-instituted orthodox christianity as it suited him. He was a tyrant, not a progressive philosopher. Ivan the Terrible was another monstrous Russian tyrant who happened to be a devout christian.

    Marx, however, had far more subtle influences than just the establishment of ugly communist systems.

    While Indian christianity may stand in opposition to the caste system (and it wasn't christianity, but the outrage of those not familiar with the practise that led to the banning of sati. It was coincidental that they were christians) but in more progressive systems, and especially where it is the dominant religion, it has always stood as an regressive force.

    The "real" teachings of christianity are in the eye of the beholder. Hitler's favourite passage from the bible was about Jesus overturning the tables of the money lenders in the temple which, he argued, showed that christianity is not a religion of peace, but one of force and strength. Many others have argued the same.

    Christianity furthermore teaches passivity to political oppression, unquestioning faith, denigrates women, etc., etc..


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