Atheists tend to be more intelligent than religious people, according to a US study.
Researchers found that those with high IQs had greater self-control and were able to do more for themselves - so did not need the benefits that religion provides.
They also have better self esteem and built more supportive relationships, the study authors said.
New evidence: A study has concluded that religious people are less intelligent than non-believers
The conclusions were the result of a review of 63 scientific studies about religion and intelligence dating between 1928 and last year.
In 53 of these there was a ‘reliable negative relation between intelligence and religiosity’.
In just 10 was that relationship positive.
Even among children, the more intelligent a child was the more probable it was that they would shun the church.
In old age the same trend persisted as well, the research showed.
The University of Rochester psychologists behind the study defined religion as involvement in some or all parts of a belief.
They defined intelligence as the ‘ability to reason, plan, solve problems, think abstractly, comprehend complex ideas, learn quickly, and learn from experience’.
In their conclusions, they said: ‘Most extant explanations (of a negative relation) share one central theme - the premise that religious beliefs are irrational, not anchored in science, not testable and, therefore, unappealing to intelligent people who ‘know better’.
‘Intelligent people typically spend more time in school - a form of self-regulation that may yield long-term benefits.
‘More intelligent people getting higher level jobs and better employment and higher salary may lead to higher self-esteem, and encourage personal control beliefs.’
Study co-author Jordan Silberman, a graduate student of neuroeconomics at the University of Rochester, said: ‘Intelligence may lead to greater self-control ability, self-esteem, perceived control over life events, and supportive relationships, obviating some of the benefits that religion sometimes provides.’
Detailed: The research analysed 63 surveys comparing intelligence levels and religious beliefs between 1928 and 2012
Research from the UK last week showed another drawback to being religious, or at least Christian - you lose out in the race for top jobs.
Official figures show nearly one in four people who have no religious belief now live in homes headed by someone with a senior executive job or a place in one of the professions.
But well under a fifth of Christians are employed in the best-paid and most influential jobs or are married to someone who is, according to the Office for National Statistics (ONS).
The last census, carried out in March 2011, showed a fall in the number of people that call themselves Christian in the UK.
Christian numbers in England and Wales, including children, fell by 4.1 million in a decade to 33.2 million.
However there was a 45 per cent rise over the same 10 years in numbers who say they have no religion, to 14.1 million.