A recent study has concluded that religious people are less intelligent, on average, than atheists.
The researchers, from the Ulster Institute for Social Research and Rotterdam University, say that faith is considered an instinct, and smarter people are better at overcoming those instincts.
The authors, Edward Dutton and Dimitri van der Linden, published their study in Springer's journal of Evolutionary Psychological Science in May.
The researchers say that a negative correlation appears valid if religion is considered an instinct and intelligence is the ability to rise above one's instincts. Dutton and van der Linden claim religion should be considered an "evolved domain" (instinct).
"If religion is an evolved domain, then it is an instinct, and intelligence — in rationally solving problems — can be understood as involving overcoming instinct and being intellectually curious and thus open to non-instinctive possibilities," Dutton said in a statement.
According to the study, the more intelligent a child is — including during the early years — the more likely he or she is to turn away from religion. And for older people, those with above-average intelligence are less likely to believe in a god.
Dutton and van der Linden also looked into the link between instinct and stress. They argue that being intelligent helps people during stressful times to consider their options and act rationally.
"If religion is indeed an evolved domain — an instinct — then it will become heightened at times of stress, when people are inclined to act instinctively, and there is clear evidence for this," Dutton said in a statement. "It also means that intelligence allows us to able to pause and reason through the situation and the possible consequences of our actions."