PSYCH1000: CHAPTER 12: DEVELOPMENT OVER THE
LIFESPAN
• Developmental psych: changes in abilities over time
• What influences development?
• Nature: changes due to maturation
• Nurture: changes due to Learning
• Interaction —> nature determines the range, nurture chooses the alternatives
Theories of Development
• Stage-like Development: discontinuous stages separated by rapid growth
• Qualitative differences, dramatic differences between abilities at each stage
• Continuous Development: smooth, continual change
• Quantitative difference, abilities simply increase over time
• Cross-sectional Design: compare ppl of different age groups at a single point in time
• Normative Approach —> typical sequence of change, look for consistency
• Longitudinal Design: repeatedly testing the same group as it grows older
• Individual Approach —> consistency is not there, look at individuals changing over time
• Sequential Design: testing several groups at one time and then again when they are older
Brain Development
• Neurons not produced after second trimester
• But brain weight increases de to glial cells & myelination
• # of synaptic connections increases rapidly
• Cortical development “mirrors” emergence of abilities
• Can’t display a behaviour until the brain is ready for it
Prenatal Development
• Zygote stage, embryonic stage, fetal stage
• 23rd chromosome in egg cell is always X
• Sperm cell X = female child (XX), sperm cell Y = male child (XY)
• Abnormal prenatal development can be caused by illness, drug use, environmental toxins
Infancy & Childhood
• Newborns & Visual Perception
• Basic machinery works at birth, but pupil not fully able to dilate, retina not fully formed
• Iris gray/blue (pigment comes later)
• Day 1: visual tracking, turn head toward objects to keep them in view
• Visual accommodation: only can focus 18-38 cm
• Visual acuity poor, improves steadily over 8 mo
• 3-4 mo = some depth perception (roughly judge object distance)
• Only binocular depth perception (can’t judge distance with a single eye)
• 4-5 mo = can reach for nearby toys
• 6-7 mo = ability to accurately grasp
• 9-10 mo = avoid deep end of visual cliff (depth cues learned)
• Sensory, perceptual abilities rapidly improve in year 1
• Can distinguish between visual/speech/odour/taste patterns
• Taste + Smell @ birth: senses very much like adults (suggests they are hard wired)
• Hearing @ birth: prefer complex sounds, sensitive to sounds in human voice range
• 1st few days = turning head toward sounds, discriminate sound sequences
• Primary sensory cortex develops first, frontal lobe develops last (takes about 21 years)
• Some perceptual-motor responses decline during first few months but recover in year 1
, • Motor Development
• At birth: most motor behaviour is reflexive (“bundle of reflexes”)
• Babinski reflex: toes fan when sole of foot is touched
• Grasping reflex: fingers clench object in hand
• Rooting reflex: head turns toward object on cheek
• Moro reflex: sudden head shift = arms swing up (keep from falling)
• Reflexive activity disappears as child grows
• Cephalocaudal principle: tendency for development to proceed head-to-foot
• Proximodistal principle: tendency for development to proceed in —> out
• Experience is critical for normal sensory / motor development
• Learn through operant and classical conditioning
• May have a primitive capacity for imitation
Jean Piaget & Cognitive Development
• Observed his own children —> found that kids think differently than adults
• *NOTE* age ranges are approximate, not completely independent
• Cognitive development depends on assimilation + accommodation
• 4 stages of cognitive development
1. Sensory-Motor Intelligence (0-2 yrs)
• Nothing exists other than own perception + motor reactions
• No self concept or concept of outside world
• Form schemas to organize concepts of the world
• At birth, we have variety of reflexes but these schemas are operating in isolation
• Coordination of activities not present until 5-7 mo
• Pseudoimitation: child can imitate but only if action was just produced
• Sensory (especially visual) feedback important at this time
• 18-24 mo = efficient imitation, representational thought (concept of external world)
• Object permanence: object continues to exist even if you can’t see it anymore
• ** object perm
2. Preoperational (2-7 yrs)
• Higher-order schemas formed
• Rules of the world / abstract rules not acquired yet (conservation laws)
• Conservation: volume/number stays the same even if container/orientation changes
• Often fail because unable to move things around in their minds
• Attend to only one aspect of a stimulus (ex height, length)
• May realize they are relevant, but don’t take them into account
• Egocentrism: inability to take the place of “the other”
• 7 y-o —> reversible thinking, develop empathy
• ** conservation, egocentrism
3. Period of Concrete Operations (7-11 yrs)
• Children learn to decenter (no longer egocentric)
• Understand transformation & conservation
• Think logically (but understanding still tied to physical world)
• ** logical thought
4. Period of Formal Operations (11+ yrs)
• Higher level of abstraction (like an adult)
• Think logically (ex. can play 20 questions by starting generally)
• ** abstract thought
Assessing Piaget’s Stages
• Piaget not consistently supported (just his own observations of his own kids)
• Kellman & Spelke: maybe 4 year-olds DO have some object permanence
• Piaget would say that kids “know” objects exist, they’re just bad at searching for them
• Piaget would say we have to LEARN that other people exist thru self-concept
LIFESPAN
• Developmental psych: changes in abilities over time
• What influences development?
• Nature: changes due to maturation
• Nurture: changes due to Learning
• Interaction —> nature determines the range, nurture chooses the alternatives
Theories of Development
• Stage-like Development: discontinuous stages separated by rapid growth
• Qualitative differences, dramatic differences between abilities at each stage
• Continuous Development: smooth, continual change
• Quantitative difference, abilities simply increase over time
• Cross-sectional Design: compare ppl of different age groups at a single point in time
• Normative Approach —> typical sequence of change, look for consistency
• Longitudinal Design: repeatedly testing the same group as it grows older
• Individual Approach —> consistency is not there, look at individuals changing over time
• Sequential Design: testing several groups at one time and then again when they are older
Brain Development
• Neurons not produced after second trimester
• But brain weight increases de to glial cells & myelination
• # of synaptic connections increases rapidly
• Cortical development “mirrors” emergence of abilities
• Can’t display a behaviour until the brain is ready for it
Prenatal Development
• Zygote stage, embryonic stage, fetal stage
• 23rd chromosome in egg cell is always X
• Sperm cell X = female child (XX), sperm cell Y = male child (XY)
• Abnormal prenatal development can be caused by illness, drug use, environmental toxins
Infancy & Childhood
• Newborns & Visual Perception
• Basic machinery works at birth, but pupil not fully able to dilate, retina not fully formed
• Iris gray/blue (pigment comes later)
• Day 1: visual tracking, turn head toward objects to keep them in view
• Visual accommodation: only can focus 18-38 cm
• Visual acuity poor, improves steadily over 8 mo
• 3-4 mo = some depth perception (roughly judge object distance)
• Only binocular depth perception (can’t judge distance with a single eye)
• 4-5 mo = can reach for nearby toys
• 6-7 mo = ability to accurately grasp
• 9-10 mo = avoid deep end of visual cliff (depth cues learned)
• Sensory, perceptual abilities rapidly improve in year 1
• Can distinguish between visual/speech/odour/taste patterns
• Taste + Smell @ birth: senses very much like adults (suggests they are hard wired)
• Hearing @ birth: prefer complex sounds, sensitive to sounds in human voice range
• 1st few days = turning head toward sounds, discriminate sound sequences
• Primary sensory cortex develops first, frontal lobe develops last (takes about 21 years)
• Some perceptual-motor responses decline during first few months but recover in year 1
, • Motor Development
• At birth: most motor behaviour is reflexive (“bundle of reflexes”)
• Babinski reflex: toes fan when sole of foot is touched
• Grasping reflex: fingers clench object in hand
• Rooting reflex: head turns toward object on cheek
• Moro reflex: sudden head shift = arms swing up (keep from falling)
• Reflexive activity disappears as child grows
• Cephalocaudal principle: tendency for development to proceed head-to-foot
• Proximodistal principle: tendency for development to proceed in —> out
• Experience is critical for normal sensory / motor development
• Learn through operant and classical conditioning
• May have a primitive capacity for imitation
Jean Piaget & Cognitive Development
• Observed his own children —> found that kids think differently than adults
• *NOTE* age ranges are approximate, not completely independent
• Cognitive development depends on assimilation + accommodation
• 4 stages of cognitive development
1. Sensory-Motor Intelligence (0-2 yrs)
• Nothing exists other than own perception + motor reactions
• No self concept or concept of outside world
• Form schemas to organize concepts of the world
• At birth, we have variety of reflexes but these schemas are operating in isolation
• Coordination of activities not present until 5-7 mo
• Pseudoimitation: child can imitate but only if action was just produced
• Sensory (especially visual) feedback important at this time
• 18-24 mo = efficient imitation, representational thought (concept of external world)
• Object permanence: object continues to exist even if you can’t see it anymore
• ** object perm
2. Preoperational (2-7 yrs)
• Higher-order schemas formed
• Rules of the world / abstract rules not acquired yet (conservation laws)
• Conservation: volume/number stays the same even if container/orientation changes
• Often fail because unable to move things around in their minds
• Attend to only one aspect of a stimulus (ex height, length)
• May realize they are relevant, but don’t take them into account
• Egocentrism: inability to take the place of “the other”
• 7 y-o —> reversible thinking, develop empathy
• ** conservation, egocentrism
3. Period of Concrete Operations (7-11 yrs)
• Children learn to decenter (no longer egocentric)
• Understand transformation & conservation
• Think logically (but understanding still tied to physical world)
• ** logical thought
4. Period of Formal Operations (11+ yrs)
• Higher level of abstraction (like an adult)
• Think logically (ex. can play 20 questions by starting generally)
• ** abstract thought
Assessing Piaget’s Stages
• Piaget not consistently supported (just his own observations of his own kids)
• Kellman & Spelke: maybe 4 year-olds DO have some object permanence
• Piaget would say that kids “know” objects exist, they’re just bad at searching for them
• Piaget would say we have to LEARN that other people exist thru self-concept
