Several research studies find that skeptics are brighter than religious believers. More than 60 scientific reports were analyzed in the journal Personality and Social Psychology Review, which said the results "showed a significant negative association between intelligence and religiosity."
Newsweek (May 18, 2017) summed up the article:
"Atheists tend to be more intelligent than religious people because they are able to rise above the natural instinct to believe in a god or gods. Having a higher intelligence" allows people to override these instincts and engage in more rational, and therefore enhanced, problem-solving behavior."
A report titled "Why Atheists are More Intelligent than the Religious" in Psychology Today (April 12, 2010) commented:
"More intelligent individuals are more likely to be atheistic than less intelligent individuals. For example, among the American sample, those who identify themselves as 'not at all religious' in early adulthood have a mean childhood I.Q. of 103.09, whereas those who identify themselves as 'very religious' in early adulthood have a mean childhood I.Q. of 97.14."
Similarly, a 2016 study by the Pew Research Center found that doubters are better-educated than believers are. Chief researcher Conrad Hackett told The New York Times:
"The higher the level of education in a country, the larger the share of people with no religion tends to be. Atheists and agnostics, or people with no religion in particular, have higher education levels than the religiously affiliated do in the United States."
Frankly, I'm surprised that the I.Q. gap is only six points. I would expect it to be larger, because most of the world's brightest people - outstanding thinkers, scientists, writers, reformers and others who left their marks on history - have been religious skeptics. Here are some, and their views:
Thomas Jefferson wrote:
"Priests of different sects dread the advance of science as witches do the approach of daylight."
Emily Bronte wrote:
"Vain are the thousand creeds that move men's hearts, unutterably vain, worthless as wither'd weeds."