Intelligence, religiosity and homosexuality non-acceptance: Empirical evidence

• Intelligence and lack of religious belief are positively correlated.
• There is less acceptance of homosexuality in Muslim nations.
• Impact curves of intelligence on homosexuality non-acceptance are constructed.
• Impact curves of disbelievers on homosexuality non-acceptance are constructed.
• Higher intelligence is associated with higher rates of homosexuality acceptance.

Our main goal is to explain the proportion of homosexuality non-acceptance, i.e., the proportion of people for whom homosexuality can never be justified. To that end, we use data on 52 countries and consider the beta regression model which is tailored for rates and proportions. We use several conditioning variables, such as average intelligence, per capita income, an indicator as to whether the country is Muslim, an income inequality index and a religious diversity index. It is noteworthy that homosexuality non-acceptance negatively correlates with average intelligence (− 0.58) and with religious disbelief (− 0.52). The estimated regression coefficients corresponding to such covariates are − 0.0207 and − 12.3636, respectively. They are both negative and statistically significant. The implication is that homosexuality non-acceptance tends to decrease when average intelligence or religious disbelief increases. We construct impact curves that measure such impacts and show how their strengths change with the relevant conditioning variables. The estimated impacts are almost always stronger for Muslim nations; they can be nearly twice as strong for such countries. The estimated impacts are also stronger when average intelligence and the prevalence of religious disbelievers are small. Bootstrap confidence intervals are also computed.