Three studies compared beliefs about natural and late blooming positive traits with those acquired through personal effort, extrinsic rewards or medicine. Young children (5-6 years), older children (8-13 years), and adults all showed a strong bias for natural and late blooming traits over acquired traits. All age groups, except 8- to 10-year-olds, treated natural and late-blooming traits as fixed essences that would persist over time and under challenging conditions. Older children and adults viewed traits acquired by intrinsic effort as more similar to natural and late-blooming traits than those acquired through bribes or medicine, suggesting that intrinsic effort itself comes to be seen as a more natural mechanism of change. A bias for the natural may therefore be an early emerging way of evaluating others that is reinforced by the ambient culture and becomes stronger with increasing age.