Treating statistics sensibly

People love to quote statistical studies to support their claims. And often its just a matter of confirmation bias. The statistical studies may not provide the support required – or may suffer from all sorts of flaws.

We see a lot of this in discussions on health, diet and life style. But I have also noticed statistics being liberally thrown around when religion and religious attitudes are discussed. If there is any area ripe for confirmation bias this is certainly it.

Consider this little graphic below which appear at a dating site OKCupid (see The REAL ‘Stuff White People Like’). Just imagine what negative conclusions one could draw about religion from that. To be fair, most references I have seen to it (all atheist – strangely, no religious sites are quoting it) do advise taking it with a grain of salt. (If you are interested have at look at the source. It provides other statistics from the study which will help make sense of this graph).

On the other hand, I have had statistical studies quoted at me which claim to “prove’ the religious people are happier, more honest, more moral, etc. Typical those quoting the studies have never bothered to check out the details and always ignore studies which might have provided different conclusions. In other words the normal confirmation bias.

Religiosity and average income of countries

The Gallup polling organisation, though, has produced some interesting statistics relating to these issues. Recently they reported data showing there was a correlation between religiosity and per capita income (see Religiosity Highest in World’s Poorest Nations). Religiosity was measured by the self declared importance of religion to individuals. Charles Blow of the New York Times provided a helpful graphic of the Gallup data (See Religious Outlier):

When the median responses are plotted for different per-capita ranges we can see a strong relationship between religiosity and per-capita  income:

This is not new. Other researcher have found a similar relationship.

Religiosity and happiness

The Gallup organisation has also reported data indicating the relationship between religiosity and  factors related to the emotional quality of life (see Religion Provides Emotional Boost to World’s Poor).

It appears that the non-religious in countries with a low average annual income were more likely to experience negative emotions than the religious. (These tend to be countries with higher religiosity).

However, for countries with higher income average annual income religiosity did not seem to influence happiness.

Digging deeper

Confirmation bias tempts people to interpret statistics in a way favourable to existing prejudices. For example, the first figure will temp atheists to claim that Christianity is associated with poor writing proficiency. And the religious may claim, on the basis of the Gallup statistics, that religiosity is correlated with individual happiness.

Unfortunately, motivated people will quote such statistics without looking any deeper than the superficial numbers.

Proper interpretation of the first figure requires consideration of sampling bias, both in the general sample (registrants at a dating site) and in the self selection for the different religious classifications.

The Gallup organisation has provided more data allowing a more sensible interpretation of their statistics. Clearly one should not use this data to claim that religion makes people happier generally. A deeper look shows conclusions should be different for higher income countries than lower income ones.

My take on the Gallup data is that religion plays a more functional role in poorer countries. It is more important to the individual in terms of social support and contact and the everyday organisation of life. On the other hand the non-religious person in such an environment may feel less social support, involvement and acceptance. Not conducive to happiness.

In contrast religion has a less important role in more developed, more secular countries. Governments and non-religious organisations are more likely to provide social support (welfare). There are far more avenues open for social involvement in secular societies. Consequently the non-religious are less likely to suffer from social exclusions or opportunities for social involvement.

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9 responses to “Treating statistics sensibly

  1. At least data from OKCupid is collected from a large population sample, so that helps minimise the effect of outliers etc. It certainly looks like there is a correlation between some beliefs and writing level, but that doesn’t necessarily indicate a causal relationship. Christians especially seem to lose out here, but there may be other factors at play not tested for in this particular set of data. Having said that, I still happily had a chuckle at the data. I’ve seen it before, my mate Eric runs a blog on economics and policy over at and has referred to the OKCupid database and findings in the past. I recommend his blog to anyone who is interested in policy issues, he touched on a diverse (some would say almost eclectic) range of issues, but seems mostly to vent frustration at the policy decision making process 🙂


  2. Ken, statistics are wonderful aren’t they

    Top 10 GDP of the world:
    1. USA – Protestant/Catholic
    2. Japan – Neither
    3. China – Neither
    4. Germany – Catholic/Protestant
    5. France – Catholic
    6. UK – Protestant
    7. Brazil – Catholic
    8. Italy – Catholic
    9. Spain – Catholic
    10. Canada – Catholic/Protestant

    Top 10 Happy Planet Index:
    1. Costa Rica – Catholic
    2. Dominican Republic – Catholic
    3. Jamaica – Protestant
    4. Guatemala – Catholic
    5. Vietnam – Buddhism (followed by Catholic)
    6. Colombia – Catholic
    7. Cuba – Catholic
    8. El Salvador – Catholic
    9. Brazil – Catholic
    10. Honduras – Catholic

    Human Development Index (HDI).
    1. Norway 0.971 (▲ 1)
    2. Australia 0.970 (▲ 2)
    3. Iceland 0.969 (▼ 2)
    4. Canada 0.966 (▼ 1)
    5. Ireland 0.965 (▬)
    6. Netherlands 0.964 (▬)
    7. Sweden 0.963 (▬)
    8. France 0.961 (▲ 3)
    9. Switzerland 0.960 (▲ 1)
    10. Japan 0.960 (▼ 2)

    What do Australia, Canada, Ireland, the Netherlands, France, and Switzerland have in common? That’s right, out of the 10 countries with the highest standard of livings, the majority of them are plurality (and in some cases majority) Catholic.


  3. Also if you want to REALLY “dig deeper” check Dinesh D’Souza or Jonathan Hill.


  4. …check Dinesh D’Souza…

    Oh yes, let’s check him out.
    By all means.
    Let’s see what a dishonest, lying quote-mining toad he is.
    Dinesh D’Souza on Richard Dawkins


  5. as usual you have nothing relevant
    want to write something coherent about statistics or the effect of religion on society?


  6. @Ropata Interesting to compare your first 2 sets of data. Aside from Brazil none of the top GDP countries appear to be especially happy. Ex-spanish or portugese colonies seem to feature significantly in the happiest nations, hence the high rate of catholocism. It raises some interesting questions about what it is that makes folk happy. Some of these countries aren’t especially wealthy, so maybe the simple life is more conducive to enjoyment than our fast-paced consumer-driven western lifestyles.


  7. Pingback: Why believe in divinity if you can’t prove it’s real? « Helleneste kai Grammateus

  8. I’ve recently started a website, the information you offer on this site has helped me greatly. Thank you for all of your time & work. “One of the greatest pains to human nature is the pain of a new idea.” by Walter Bagehot.


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