Summary: A new study investigates whether religiosity is associated with lower measured intelligence. The researchers find that religious people tend to depend more on intuitive responses than on analytic reasoning during decision-making tasks. They suggest that cognitive training could help religious individuals preserve their beliefs while reducing an over-reliance on intuition in situations where logic is required.
Source: BPS
Do religious people score lower on intelligence tests?
There are many highly intelligent people with strong religious convictions, but several large-scale studies have reported an inverse association between religiosity and IQ scores. In a new paper from researchers at Imperial College London, Richard Daws and Adam Hampshire investigate why religiosity and intelligence appear to be related. Their study, published in Frontiers in Psychology, explores whether the effect reflects a general difference in intelligence or a specific tendency to rely on intuition rather than deliberative reasoning.
The issue has wider social relevance. If the share of the global population holding religious beliefs continues to grow — as some projections indicate — questions arise about how such population-level trends relate to cognitive performance measures. Rather than concluding that religious belief causes lower overall intelligence, Daws and Hampshire ask whether the observed patterns are better explained by a bias toward intuitive problem solving that produces errors when intuition conflicts with logic.
Study design and methods
The researchers analyzed data from more than 63,000 participants who completed an online cognitive assessment lasting about 30 minutes. The assessment included 12 tasks designed to measure planning, reasoning, attention and working memory. Participants also reported whether they identified as religious, agnostic or atheist, and indicated the strength of their religious convictions.
The large sample allowed the authors to control for socio-demographic factors such as age, education and country of origin. They also examined variation across different religious groups and levels of dogmatism to see whether the relationship between religiosity and task performance was uniform or context-dependent.
Key findings
Overall, atheists outperformed religious participants on reasoning tasks, with agnostics typically scoring between atheists and believers. This pattern held after adjusting for age and education. Crucially, the deficit associated with religiosity was most pronounced on tasks that intentionally created conflict between an immediate, intuitive response and the correct, analytically derived answer.
For example, a demanding version of the Stroop Task (a “colour-word remapping” task) — which is engineered to pit an intuitive response against a logical one — revealed the largest differences between groups. Religious participants, especially those reporting stronger dogmatism, were more likely to follow the intuitive response even when it led to errors. By contrast, on a difficult deductive reasoning or matrix-reasoning task where no obvious intuitive alternative existed, group differences were much smaller.
Working memory performance showed only minor differences between groups, suggesting that the religiosity effect is not primarily driven by deficits in basic memory capacity or general intellect. Instead, the pattern supports the interpretation that behavioral or cognitive biases — a greater propensity to accept intuitive answers — underlie the observed association.
Interpretation and implications
Daws and Hampshire conclude that their results “provide evidence in support of the hypothesis that the religiosity effect relates to conflict [between reasoning and intuition] as opposed to reasoning ability or intelligence more generally.” In other words, the data are consistent with the idea that religiosity is linked to a cognitive style that favors intuitive, fast responses in situations where deliberative, effortful reasoning would yield better solutions.
This has practical implications. If stronger religious conviction increases the likelihood of defaulting to intuition, that tendency could affect decision-making in everyday contexts where intuition and logic conflict. However, the study does not show that religious belief reduces overall life achievement or practical success. Nor does it claim that religion makes individuals incapable of analytic thought.
One promising implication the authors note is that cognitive training might help people who hold religious beliefs to reduce an over-reliance on intuition in contexts where analytical reasoning is important. Such training would aim to strengthen the ability to detect and resolve conflicts between immediate impressions and reasoned conclusions without requiring changes in personal belief.
Authors: Richard Daws and Adam Hampshire, Imperial College London
Published in: Frontiers in Psychology
Sample size: Combined N = 63,235 from two large internet-cohort studies
Main conclusion: The negative relationship between religiosity and reasoning performance appears to be driven by a bias toward intuitive responses when intuition and logic conflict, rather than by a broad deficit in intelligence or working memory.
Original Research DOI: 10.3389/fpsyg.2017.02191
Abstract (shortened)
The negative relationship between reasoning and religiosity is underpinned by a bias for intuitive responses specifically when intuition and logic are in conflict. Atheists outperformed religious individuals on reasoning tasks that manipulate conflict; group differences were minimal for tasks without intuitive distractors and for working-memory measures. These results support the hypothesis that behavioral biases rather than impaired general intelligence explain the religiosity effect.