Stupid people are more likely than eggheads to believe in God, a controversial new study claims.
In a move that is bound to offend millions of churchgoers, a British psychologist says he has found a link between having a high IQ and being an atheist.
The discovery helps explain why university academics are less likely to be religious than almost anyone else, he says.
Church leaders dismissed the study as absurd and simplistic. They pointed out that many of the greatest brains in history believed in God.
The study came from Prof Richard Lynn - a retired academic at the University of Ulster who has courted controversy in the past with studies looking at sex, race and intelligence.
His latest work, published today in the scientific journal Intelligence, compared religious belief and average national IQs in 137 countries.
Information about faith was based on surveys carried out in 2004.
Prof Lynn found that in only 17 per cent of countries did the proportion of people who believe in God fall below 80 per cent.
'These are virtually all the higher IQ countries,' he said.
Controversial: Prof Richard Lynn's study has infuriated the church community
When he broke down the statistics, he found a strong link between intelligence and faith. Countries with a lower national IQ tended to have the most believers.
One of the few exceptions was America - a high IQ country where only 10 per cent of people don't believe in God.
In Britain - another high IQ country - the figure is around 40 per cent, he said.
'One factor that could provide a possible explanation for this is that many Americans are Catholics and the percentage of believers in Catholic countries in Europe is generally much higher than in Protestant countries,' he said.
'A further possible factor might be that that the number of emigrants from Europe went to the United States because of their strong religious beliefs - so it may be that these beliefs have been transmitted as a cultural and even genetic ally to subsequent generations.'
Prof Lynn said a survey of fellows of the Royal Society - Britain's science academy - found that only 3.3 per cent believed in God at a time when nearly 70 per cent of Britons described themselves as having a faith.
Prof Lynn said most primary school children believde in God - but that they lose their faith as they get older and begin to question the world.
But Prof Gordon Lynch of Birkbeck College, London, said the study had failed to take into account complicated economic, historical and social factors that explained different IQ and 'faith' levels in countries.
'Linking religious belief and intelligence in this way could reflect a dangerous trend, developing a simplistic characterisation of religion as primitive,' he said.
Ben Wilson a spokesman for the Church of England said: 'The idea that believers are not intelligent is absurd.
'Some of the greatest thinkers through history have been people of faith. You don't have to leave your brain in the church porch.'