No. This implies that desire for children or religiosity implies stupidity. I don't see much evidence for this outside pop-atheist iamverysmart cliches.

People with lower intelligence may be just as likely to adopt a short term hedonic lifestyle and use contraception more. Totally depends on cultural trends.

What we are selecting for is any heritable trait that might durably make people more likely to intentionally reproduce. That could be a lot of things: a stronger biological clock, later menopause for women, changes in cognitive patterns to the degree that they are heritable, maybe even longevity or longer healthspan. Its complex and hard to predict.