The Critical Period Hypothesis Period Hypothesis The innatist perspective is often linked to the Critical are genetically (CPH)-the hypothesis that animals, including humans, at specific times programmed to acquire certain kinds of knowledge and skill impossible to life. Beyond those critical periods, it is either difficult or that chil acquire those abilities. With regard to language, the CPH suggests dren who are not given access to language in infancy and early childhood (because of deafness or extreme isolation) will never acquire language if these deprivations go on for too long