|Fig 1 of Purzycki et al. People who believe in moralistic|
gods seem less likely to cheat their co-religionists.
However the paper "Moralistic gods, supernatural punishment and the expansion of human sociality" by Purzycki et al has just been published online by Nature and seems rather more interesting. They use a modified the random allocation game in which participants play in private with 30 coins, two cups and a fair die with three sides of one colour and three sides of another colour. They mentally choose one of the cups and then roll the die. If one coloured side comes up, players are asked to put the coin into the cup they mentally chose. As cup selection occurs only mentally, participants can overrule the die in favour of one of the cups without anyone else observing their decision. If people play by the rules and thereby allocate the coins impartially, the mean number of coins in each cup should be 15, and the distribution around this average will be binomial. This allows us to test for systematic deviations from this distribution.
People who believe in a moralistic god who punishes wrongdoing are significantly more likely not to cheat than those who don't (Log odds ratio 1.26 +0.16 P less than 0.001) and this is the same whether the recipient is a local co-religionist or a distant co-religionist. None of the other experiments has a really low P value.
What is remarkable about this study is that it was not conducted amongst the usual WIERD subjects but in Tanna, Hadza, Mauritius, Pesqueiro, Tyva Republic, Yasawa and Lovu (both places in Fiji). So it is rather more persuasive of the idea that believe in such deities encourages the evolution of eusociality.
As I have long said, Dawkins and co refuse to acknowledge the obvious fact that religions like Christianity offer a clear evolutionary advantage.