Chapter 11: Development over the life span
Major issues and Methods
• Nature and nurture
• Critical period and sensitive period
- Critical period: an age range in which certain experiences must occur for development to proceed
normally or along a certain path.
- Sensitive period: an optimal age range for certain experiences, but normal developments are still
possible at other times.
• Continuity vs. discontinuity. Is development continuous and gradual, or progressing through
qualitatively distinct stages?
• Stability vs. change. Do our characteristics remain consistent as we age?
Five developmental functions
(A) No change – abilities present at birth that remain constant across the life span;
(B) Continuous change – abilities absent/immature at birth that mature gradually over age;
(C) Stages (discontinuity) - abilities that emerge in stages, with relatively rapid shifts.
(D) Invert U-shaped function - Abilities that emerge after birth, peak, and then disappear with age.
(E) U-shaped function – abilities present early in life, disappears temporarily, and re-emerges later.
Cross-sectional people of varying Pro: Widely used b/c Cons: different age
design ages studied data from many age groups (cohorts) grew
simultaneously groups can be up in different
collected relatively historical periods.
Longitudinal design Same people studied Everyone is exposed Time consuming and
over a period of time. to the same historical sample may shrink
time frame. substantially.
Sequential design Combines both Most comprehensive Most time consuming
approaches and costly.
- Consists of three stages:
- zygote(fertilized egg)
- Embryo (2-8 week), placenta and umbilical cord develop at the start of this stage.
- Fetus (9 week), lasts until birth, muscles become stronger and other bodily systems continue to
1 - By 28 weeks, the fetus attains the age of viability, meaning it is likely to survive outside the womb.
Teratogens – environmental agents that cause abnormal prenatal development.
Fetal Alcohol Syndrome (FAS) – consists of a group of abnormalities resulting from prenatal exposure to
maternal alcohol consumption which include facial abnormalities, small malformed brains and small stature.
Fetal Alcohol Effects (FAE) – the less severe pattern of symptoms.
Infancy and Childhood
Preferential looking procedure - developed by Robert Fantz; Fantz placed infants on their backs, showed
them two or more stimuli at the same time, and record how long they looked at each stimulus, and discovered
that newborns have visual preference for complex patterns.
Visual habituation procedure – the same stimulus is presented repeatedly until infant looking time declines.
When a novel stimulus is presented, infants usually look longer at the novel rather than the familiar stimulus.
This is evidence that infants have a memory and that they discriminate between familiar and novel stimuli.
The use of habituation and other test procedures demonstrate that infants are born with the capacity to
recognize, respond to, and remember their primary caretakers and to learn other important information about
significant events in their environment.
Maturation- is the genetically programmed biological process that governs our growth.
Physical and motor developments follow several biological principles.
- The cephalocaudal principle reflects the tendency for development to proceed in a head-to-foot
direction. Thus the head of a fetus/infant is disproportionately large, because physical growth
concentrates on the head and proceeds toward the lower part of the body.
- The proximodistal principle states that development begins along the innermost parts of the body
and continues towards the outermost parts. Thus a fetus’s arms develop before its hands and
fingers, and at birth infants can control their shoulders, but not their hand or fingers.
Experience plays a critical role in the development of sensory, perceptual, motor, and physical development.
• Biological sets limits on environmental influences.
• Environmental influences can be powerful.
• Biological and environmental factors interact.
Piaget’s Stage Model
- Children’s thinking changes qualitatively with age, and that it differs from the way adults think.
- Cognitive development results from interplay of maturation and experience, and he viewed children
as natural-born “scientists” actively exploring and seeking to understand their world.
- To achieve this understanding, the brain builds schemas (organized patterns of thought and
action). Cognitive development occurs as we acquire new schemas, and as our existing schemas
become more complex.
2 - Two key processes are involved: Assimilation (process by which new experiences are
incorporated into existing schemas) and Accommodation (the process by which new experiences
cause existing schemas to change)
Stage Age(years) Major Characteristics
Sensorimotor Birth – 2 - Infant understands world through sensory and motor
- Achieves object permanence
- Emergence of symbolic thought
Preoperational 2 -7 - Symbolic thinking; child uses words and images to
represent objects and experiences; pretend play.
-Thinking displays egocentrism, irreversibility and
Concrete 7-12 - Child can think logically about concrete events.
Operational - Grasps concepts of conservation and serial ordering
Formal 12 on - Adolescent can think more logically, abstractly and
- can form hypotheses and test them systematically.
- Although the general cognitive abilities associated with Piaget’s four stages appear to occur in the same order
across cultures, children acquire many cognitive skills at an earlier age than Piaget believed.
- Also the cognitive development within each stage seems to proceed inconsistently.
Vygotsky: The Social Context of Cognitive Development
- He emphasized that cognitive development occurs in a socio-cultural context.
- Each child has a zone of proximal development, reflecting the difference between what a child can do
independently and what the child can do with assistance from others.
Theory of mind - refers to a person’s beliefs about how the “mind” works and what other s are thinking about.
Kohlberg’s stage Model
Level of Moral Reasoning Basis for Judging what is moral
Level 1:Preconventional Actual/anticipated punishment and rewards, rather than
Stage 1: Punishment/Obedience Obeying rules and avoiding punishment
Stage 2: Instrumental/ hedonistic Self-interest and gaining rewards
Level 2:Conventional Conformity to the expectations of social groups; person
adopts other people’s values
Stage 3: Good child orientation Gaining approval and maintaining good relations with
Stage 4: Law and Order orientation Doing one’s duty, showing respect for authority, and
maintaining social order
Level 3: Postconventional Moral principles that are well thought out and part of
one’s belief an