(I) Infants all over the world begin to smile at about the same age. (II) Whether they are born in a remote African village or in a middle class American home, it seems to make no difference. (III) Unfortunately, this usually occurs when they see familiar faces or hear familiar voices. (IV) This suggests that age is more important in determining the onset of smiling than are the conditions of rearing. (V) Moreover, blind babies smile at about the same age as sighted-infants, suggesting it is an innate response.