Those abilities in infants designated by Myrtle B. McGraw (1899-1988) to have a recent evolutionary history and which are therefore more susceptible to the effects of experience than those she classified as phylogenetic skills. Not a distinction that is in much use today.
See Ability, Experience, Fundamental movement patterns, Ontogenetic development, Phylogenetic abilities/behaviors (as opposed to ontogenetic abilities), Phylogenetic skills, Skill (general)