Countries differ with respect to human rights. Using the cross-country CIRI data (Cingranelli & Richards), the authors tested two theories. The cognitive-moral enlightenment theory going back to Piaget and Socrates postulates that individuals and nations with higher levels of cognitive ability think and behave in a way more conducive to human rights. The culture-religion theory going back to Weber, Sombart and Voltaire postulates that different religious beliefs shape attitudes, and propel societies toward institutions that are more or less supportive of human rights. Cognitive ability had a positive impact on human rights but its effect varied depending on the country sample. More important was religion, both in cross-sectional and longitudinal models. Percentage of Christians had a positive impact (r=.62, total effect beta=.63), percentage of Muslims had a negative one (r=-.57, total effect beta=-.59). Political institutions are highly correlated with human rights, but religion is the decisive background factor.