While it’s often assumed that smarter people are more ethical or morally developed, past research has produced conflicting results. Some studies have linked higher intelligence to greater support for liberal values like compassion and fairness, while others have found that smarter individuals are less likely to endorse moral principles rooted in loyalty, tradition, or purity. In short, the relationship between intelligence and moral values was unclear. The present study aimed to clarify that relationship by using an improved measure of moral foundations and a well-established test of cognitive ability.
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In both studies, the researchers used statistical models to examine the relationship between intelligence and moral foundations. They tested four competing hypotheses. One predicted no relationship at all. Another proposed that intelligence would strengthen all moral foundations. A third suggested that smarter people would favor individualizing foundations but reject binding ones. The final hypothesis, called the Morality Suppression Model, predicted that intelligence would be negatively related to all moral foundations.The results supported the Morality Suppression Model. In both studies, higher intelligence was linked to weaker endorsement of every moral foundation. People with higher scores on verbal, numerical, and abstract reasoning tests rated care, equality, proportionality, loyalty, authority, and purity as less important to their moral identity.
I think this is just because they’re aware that morals are culturally relative. They probably do have morals but they’re more specific and debatable.