Development

Three Minute Review NONVERBAL COMMUNICATION facial expressions fake vs. zygomatic smiles eye contact conveys dominance, confidence, attraction body language gestures why do people gesture on the phone? interactional synchrony intonation deception

children’s overgeneralization language acquisition critical periods LANGUAGE DEVELOPMENT Skinner vs. Chomsky operant conditioning vs. language instinct children’s overgeneralization grammatical errors and “Wug test” language acquisition critical periods ~6 months for learning phonemes ~6 years for learning grammar

Test Yourself A child who uses the word “wawa” to refer not only to water but to milk, juice and other drinks is: overextending the word underextending the word demonstrating conditioning of the word “wawa” with any liquid babbling autistic

Development Physical Development Cognitive Development Social Development

Brain Development

Brain Development during pregnancy, the brain can be highly susceptible to teratogens radiation, drugs, viruses, toxins explanation for morning sickness? fetal alcohol syndrome cluster of defects occurring in infants born to mothers that drink heavily during pregnancy leading cause of mental retardation even moderate drinking (e.g., three beers a day) may lead to children with a lower IQ and shorter attention span

Neural Development Grow, then prune Neural Darwinism make too many neurons, then prune the ones you’re not using “use it or lose it” there are 30-60% more neurons in the fetus than in the adult brain

Myelinization basic sensory and motor areas become myelinated early association areas become myelinated later

Cognitive Development The infant’s world is a “blooming, buzzing confusion” -- William James How can you study perception and cognition in a non-verbal being (preverbal child, animal)? Visual tracking Preferential looking Eye movement monitoring Habituation Sucking

Visual Tracking newborns will track facelike stimuli innate preference for faces?

Orienting and Habituation Orienting reflex humans, including infants, pay more attention to novel than familiar stimuli Habituation infants get bored with repeated presentations of the same thing Habituation paradigm repeat the same stimulus over and over again, then change it slightly does infant spend more time looking at new stimulus?

Preferential Looking present two stimuli on either side of centre watch where infants look in the best studies, the mom and experimenter are blind to the stimuli spontaneous looking preferences e.g., infants prefer high contrast habituation familiarize infant with one stimulus, then present it in combination with a new stimulus infant looks more at new stimulus  infant could tell the difference infant looks equally at old and new stimuli  infant couldn’t tell the difference

What have we learned? Although newborns can see faces, faces must appear very blurry to them

Eye Movements newborns look at outside features of faces older infants, like adults, spend much time looking at eyes and mouth

Behavior Visual Cliff Will the baby crawl over the glass to get to mom? mobile infants won’t pre-mobile infants did not appear bothered when placed on the glass

Sucking Response newborns suck more when they hear their native language newborns suck more when they hear their mom’s voice

Critical Periods (See Gray, pp. 135) Imprinting Konrad Lorenz 1903-1989 Imprinting baby ducks and goslings will follow on the first individual they encounter, even if it’s a human rather than the mother imprinting must happen within five days after hatching Critical period: A period in development during which some event has a long-lasting influence on the brain and behavior that it would not have if it occurred outside that period

Does Development Occur Continuously or in Stages?

Jean Piaget Piaget, a Swiss psychologist, believed that “children are active thinkers, constantly trying to construct more advanced understandings of the world” These “understandings” are in the form of structures he called schemes Jean Piaget 1896-1980

Assimilation and Accomodation Schemes are frameworks that develop to help organize knowledge Assimilation - process of taking new information or a new experience and fitting it into an already existing scheme Accommodation - process by which existing schemes are changed or new schemes are created in order to fit new information

Piaget’s Approach Primary method was to ask children to solve problems and to question them about the reasoning behind their solutions Discovered that children think in radically different ways than adults Proposed that development occurs as a series of ‘stages’ differing in how the world is understood

Sensorimotor Stage birth - 2 years Information is gained through the senses and motor actions (looking, touching, mouthing) In this stage child perceives and manipulates but does not reason Infant gradually becomes aware of relationship between own actions and their effects on environment Object permanence is acquired

Sensorimotor Development

Object Permanence 8 - 10 mos.: Infant begins to understand that objects exist even when not in view

Preoperational Stage 2 - 7 years Represents things with words and images but lacks logical reasoning Can think symbolically (e.g., pretending a stick is a gun) Thinking is egocentric: has difficulty taking the viewpoint of others Fails to understand conservation What does the doll see?

Conservation of Number Is there the same number in each row?

Conservation of Length Which stick is longer?

Conservation of Volume Which container has the most volume

Conservation of Mass Which is bigger?

Concrete Operational Stage 7-12 years Can think logically about objects and events Can see other’s perspective Achieves conservation of number (~age 6), mass (~age 7) and weight (~age 9)

Formal Operational Stage 11 years and up Can think logically about abstract propositions and test hypotheses systematically Can understand hypothetical propositions e.g., If all animals can fly and if rhinoceroses are animals, then all rhinoceroses can fly. Becomes concerned with the the future and ideological problems Not achieved by all adults

Critiques of Piagetian Theory Underestimates children’s abilities Overestimates age differences in thinking Vagueness about the process of change Underestimates the role of the social environment tests were done on Western European kids Vygotsky argued culture and social interaction were critical to development Lack of evidence for qualitatively different stages Not well integrated with neuroscience

Contradictory Experiments In preferential looking experiments, 4 month old infants who did not demonstrate object permanence nonetheless looked longer at an unexpected occlusion event Preoperational children chose the column with more M&Ms

Information Processing Perspective Focuses on the mind as a system, analogous to a computer, for analyzing information from the environment Developmental improvements reflect increased capacity of working memory faster speed of processing new algorithms (methods) more stored knowledge