Earlier a particular ability appears, the more likely it is to be under the influence of genetic factors
Estimates of genetic influence = heritability
Chomsky (1965) proposed language is gained through the use of an innate language acquisition device
Freud's theory of aggression as being an innate drive (called Thanatos)
Characteristics + differences that are not observable at birth, but which emerge later in life = product of maturation
We all have an inner "biological clock" which switches on (or off) types of behavior in a pre-programmed way
Bodily changes that occur in early adolescence at puberty
Nativists also argue that maturation governs the emergence of attachment in infancy, language acquisition, and even cognitive development