Posted by on Feb 27, 2013 in God, Logic, Mathematics, Psychology | 9 comments

# Believers are bad at mathematics?

I just read an interesting article by Matthew Hutson at Huffington Post entitled What Kind of Thinker Believes in God?.  Hutson summarises an article in the Journal of Experimental Psychology - Divine Intuition: Cognitive Style Influences Belief in God - in which  a team of Harvard psychologists showed that there is a correlation between belief in God and performance on the well-known Cognitive Reflection Test (CRT).

Here are the questions from the CRT:

1.  A bat and a ball cost \$1.10 in total.  The bat costs \$1.00 more than the ball.  How much does the ball cost?

2.  If it takes five machines five minutes to make five widgets, how long does it take 100 machines to make 100 widgets?

3.  In a lake, there is a patch of lily pads.  Every day, the patch doubles in size.  If it takes 48 days for the patch to cover the entire lake, how long would it take for the patch to cover half of the lake?

They’re actually quite fun questions, regardless of whether you think they have anything to do with belief in God.  Why not give them some thought, and write down your answers?  Better yet, why not let me know what you got?

Each question suggests an intuitive but incorrect answer.  (Do you need to check your working now?)  Most people will find that this answer has formed in their head before they even try to solve the problem.  So to actually arrive at the correct answer, you need to second guess your intuition and overcome it with your reasoning skills.

The main finding of the JEP article is that “participants who gave more intuitive answers on the CRT reported stronger belief in God”.

Obviously, the CRT is not a perfect predictor, as there are plenty of professional mathematicians who are deeply religious – and plenty of atheists who wouldn’t know logic if it bit them in the modus ponens.  But the predictive power of the CRT is very good, as the following figure from the article shows:

Now, why might this be the case?  The HuffPost article summarises some of the conclusions from the JEP article as follows:

Psychologists who study the origins of religion say belief in God relies on several intuitions, including a teleological bias (the assumption that certain objects or event were designed intentionally) and Cartesian dualism (the belief that mind can exist independently of the body).  So to become an atheist one must second-guess these automatic ways of thinking.

(See the General Discussion section of the JEP article for a more thorough analysis.)

I can certainly vouch for the fact that I used to think the existence of God and the independence of the mind and brain were extremely obvious.  It was not until I eventually found myself thinking critically about these things that I set out on the path that ultimately led to atheism.  In fact, being an ex-believer, I was interested that the study also showed there was no correlation between religious upbringing and performance on the CRT, “suggesting a causal relationship between cognitive style and change in belief over time”.

Oh well, what did you get?  I won’t post the CRT answers here, but if you want to see them, the HuffPost article has ‘em!

References.

Shenhav, A., Rand, D. G., & Greene, J. D. (2011, September 19).
Divine Intuition: Cognitive Style Influences Belief in God.
Journal of Experimental Psychology: General.
Advance online publication. doi: 10.1037/a0025391

• Peter White

I guess I’m not very intuitive. I sat down and worked through all the answers because I didn’t trust my intuition to get them right. I had to write out 3 equations for the first question before I knew I had it.

• http://www.facebook.com/Scott1328 Tim McCollough

in no particular order 47,.05,5

• Stefano S.

I wouldn’t say it’s mathematics. Those questions are more about logic and intuition than anything else.

• Reasonably Faithless

Yes, not really mathematics as such (although they involve mathematical concepts), but I thought the title was snappier that way.

• DRC

It’s interesting that those who had a negative change in belief pretty much got all 4 questions right. Of the people who got 1 wrong, only a small proportion had a negative change in belief, and everyone else had a positive change.

This suggests that losing one’s belief is quite rare.

• f_galton

I prayed for the right answers and got all three correct.

• Reasonably Faithless

I’m glad you did! Do you think you would have got any incorrect otherwise?

• Nick Sewell
• Reasonably Faithless

That is fantastic. Thanks!!