3.1 Physical, Perceptual, and Language Development Developmental Psychology: the study of changes that occur as an individual matures.

I. Newborns Grasping reflex: an infant’s clinging response to a touch on the palm of his or her hand. Rooting Reflex: an infant’s response in turning toward the source of touching that occurs anywhere around his or her mouth.

II. Physical Development 95% of infants are between 5.5 and 10 pounds and are inches in length. Maturation: the internally programmed growth of a child.

III. Perceptual Development 3 or 4 month old infants show a strong preference for faces and patterns, suggesting that infants are born with and develop visual preferences. Visual Cliff

IV. Language 1 year= Babbling begins and increases. Usually says his or her first word like baba or mama. Babbles begin to sound more like the langauge they are brought up in. 2 years= Begins to speak in paired words. No ball. 3 years= acquires more grammatical knowledge. Average size of vocabulary over 5000 words. 4 years= more grammatical rules. EX: Why is Jenny crying? Average vocabulary about 9000 words.

Animal and Language Chimps: Can acquire language skill equivalent to that of a two year old. The can learn ASL. Washoe by age 5, knew more than 160 signs. Chimps use words as symbols but cannot apply grammatical rules.Washoe

Genie