V. M. Westerberg's super brief developmental theories series.

1. V.M.WESTERBERG’S SUPER BRIEF THEORY SERIES
LIFETIME DEVELOPMENTAL MILESTONES
Infancy and Toddlerhood: Birth - Age 2
Biological
• Body doubles in height and quadruples in weight
• Neurons grow in increasingly dense connections,
becoming coated with layers of myelin, and enabling
faster and more efficient message transmission
• Experiences help to fine tune the brain's responses
to stimulation
• Motor skills progress from simple reflexes to
coordinated motor abilities, such as grasping and
walking
• Sensory and perceptual abilities develop rapidly
Cognitive
• Basic structure of language learned through baby
talk with adults
• First communication emerges through crying, then
cooing and babbling
• Language skills progress from speaking a few words
by age 1, to constructing sentences by age 2
• Awareness of world progresses through immediate
sensorimotor experiences to mental representations
of events
• Thinking includes concept of object permanence:
objects still exist when out of sight or awareness
• Ability to grasp conceptual categories begins; by
age 2 numerous definite concepts develop
Piaget’s sensorimotor stage
Psychosocial
• Emotional responses change from basic reactions to
more complex, self-conscious responses
• Independent behaviors increase with parental
encouragement around feeding, dressing, and toilet
training
• Parents and infants respond to each other by
synchronizing their behavior
• Development of secure attachment sets stage for
child's increasingly independent exploration
• Ability to relate to playmates emerges by end of
period
• Early personality traits, such as introversion and
extroversion, develop
Erikson’s trust vs mistrust, autonomy vs doubt.

2. Early Childhood: Ages 2 - 6
Biological
• Brain is 90% of its adult weight by age 5,
developing faster than any other body part
• Myelination proceeds at different rates in various
areas of the brain, resulting in different rates of
readiness for certain types of activities
• Physical strength increases and body proportions
become more adult-like
• Athletic skills, such as running, jumping, and
hopping, dramatically improve
• Fine motors skills, such as writing and drawing,
develop slowly
• Gender differences in motor skills begin to emerge
Cognitive
• Use of mental representations and symbols, such as
words, begins
• Ideas about the world continue to be somewhat
illogical
• Social interactions with parents and playmates
teach about the world
• Language abilities develop rapidly, resulting, on
average, in a 14,000-word vocabulary and
extensive grammatical knowledge by age 6
• Ability to adjust communication to audience begins
• Metacognition, the ability to think about thought,
forms
Piaget’s pre-operational stage (2-7)
Psychosocial
• Play alone or with others becomes increasingly
complex and imaginative
• Increased energy fosters ability to initiate new
activities, especially if child receives praise for
actions
• First awareness of gender roles emerge
• Desire for independence and control over
environment increases, making parents' supervisory
role more challenging
• Parenting style influences child's psychosocial
development
• Socialization in school encourages thinking about
world outside the home
Erikson’s autonomy vs doubt (1-3),
Initiative vs guilt (3-6)

3. Middle Childhood: Ages 7 - 9
Biological
• Brain growth slows down
• Physical growth slows, but slight height spurts occur
• Expansion of heart and lung capacities supports
more physical endurance
• Athletic and fine motor skills become more refined
Cognitive
• Ability to understand logical principle develops
• Memory capacity and ability to use mnemonics
expands
• Metacognition, the ability to think about thought,
enables organization of own learning
• Use of language becomes more analytical
• Proficiency in more than one language code may
begin, sometimes resulting in bilingualism
Piaget’s preoperational stage
Psychosocial
• Peer group becomes more significant as dependence
shifts to friends for help, loyalty, and sharing of
mutual interests
• Awareness of and involvement in outside world
increases awareness of family, economic, and
political conditions
• Motivational systems build around achievement,
competence, and affiliation
• Coping strategies develop for problem solving and
stress tolerance
• Interpersonal strategies develop to aid in
understanding others' behaviour
Erikson’s Initiative vs Guilt (3-6)
Industry vs Inferiority (6-12)

4. Late Childhood: Ages 10 - 12
Biological
• Puberty begins with rising hormone levels
• Girls' growth spurt begins with gains in height,
weight, and musculature
• Gender specific physical changes appear within first
year: enlargement of breasts in girls and testes in
boys
• In physical maturation, boys lag, on average, 2
years behind girls
• Variations in onset of puberty impact personality
development
Cognitive
• Logical thought progresses to abstract thinking
• Planning skills and memory strategies improve
• Long-term knowledge base grows
• Language skills expand to include synonyms,
categories, double meanings, metaphors, humor,
and complex grammatical structure
Piaget’s concrete operational stage
Psychosocial
• Changes in physique, sexuality, cognitive
functioning, and society's treatment may challenge
sense of self
• Appreciation of connection between moral rules and
social conventions strengthens
• Peer groups often divide into cliques
• Awareness of gender stereotypes continues to
increase
• Issues increase around autonomy, sibling rivalry,
and separation from family
Erikson’s Industry vs Inferiority (6-12)

5. Early Adolescence: Ages 13 - 15
Biological
• Body continues to grow in height and weight
• Girls growth spurt peaks, while boys typically begin
it
• Motor performance gradually increases, but often
levels off for girls
• Girls usually start to menstruate and boys to
ejaculate
Cognitive
• Formal operational reasoning, the capacity for
abstract, scientific thought, emerges
• Thinking becomes more self-conscious, idealistic,
and critical
• Metacognition and self-regulation further develop
• Vocabulary expands to include abstract words
• Understanding and grasp of complex grammar
continues to improve
• Ability to grasp irony and sarcasm develops
Piaget’s formal operational stage
Psychosocial
• Issues of identity emerge, potentially leading to
crisis in sense of self
• Sexual orientation begins to emerge
• Psychological disorders and sociocultural-
adaptational disorders may emerge
• Strives for autonomy in relation to family continues
to increase, and parent-child conflicts more likely to
occur
• Friendships have greater emphasis on intimacy and
loyalty
• Conformity to peer pressure increases
Erikson’s Identity vs (role) Confusion (12-19)

6. Late Adolescence: Ages 16 - 19
Biological
• Boys' growth spurt peaks, and growth is mostly
complete by end of this period
• Boys develop deeper voices and patterns of facial
hair, and typically grow taller than their female
peers
• Girls tend to grow wider in the hips, and breast
development continues for several years
• Girls' motor performance peaks, while boys'
continues to improve
Cognitive
• Reasoning through problems in symbolic terms and
through use of formal logic improves
• Fluid intelligence, the ability to cope with new
problems and situations, is reached by the end of
this period
• Ability to understand and integrate rules into sense
of self becomes basis for character development
Piaget’s formal operational stage
Psychosocial
• Development of identity continues in relation to
adult world
• First dating begins process of developing and
maintaining intimate relationships
• Cliques decline in importance
• Identity achievement greatly influenced by personal
factors, including family and peer relationships with
family and peers, and economic and political
circumstances
• Increased assertiveness and lack of self-discipline
often create conflicts with parents
• Sexual orientation continues to develop
• Introduction begins to the world of work and career
planning
Erikson’s Identity vs (role) Confusion (12-19)

7. Early Adulthood: Ages 20 - 40
Biological
• Physical functioning increases through the 20's and
peaks at about age 30, but can be maintained
through exercise
• Body shape changes, with gradual increases in
weight and body fat and decreases in lean muscle
mass
• Efficiency of many organ systems begins to diminish
at the rate of about 1% a year
• Sexual responsiveness remains high throughout this
period, with some slowing in men
• Physical appearance changes; gray hair and
wrinkles develop toward end of this period
Cognitive
• Thinking may become practical and dialectical to
adapt to the inconsistencies and complexities in
daily experiences
• Short-term memory peaks
• Wisdom and expertise begin to develop
• Vocabulary and knowledge continue to grow
through work interactions and everyday problem-
solving
Piaget’s formal operational stage
Neo-Piagetian postformal stage
Psychosocial
• Issues of identity and intimacy peak by age 30
• Need for affiliation filled by friends and often a
marriage/partner
• Friendships become particularly important for
people who are single
• Need for achievement often met through
satisfactory work consistent with personality and
abilities
• Personality traits most likely to change up to age
30, with additional maturation continuing into the
40's
Erikson’s Intimacy vs Isolation (20-45)

8. Middle Adulthood: Ages 40 - 65
Biological
• Gradual changes continue in appearance of skin,
hair, and body shape
• Gradual changes occur in hearing and vision,
including presbyopia, the inability to focus on near
objects
• Menopause begins in women
• Health and potential onset of disease affected by
preventive behaviors, many of which vary by social
class
Cognitive
• Fluid intelligence declines while crystallized
intelligence remains steady or increases
• Intellectual abilities dependent on speed and
novelty decrease, while abilities involving
knowledge about the world and vocabulary increase
• Reaction time and mental processing speed slow
• Short and long-term memory remain relatively
stable
• Cognitive abilities related to experience and
intelligence flourish, leading to further formation of
expertise
• Maintenance of cognitive skills as well as
opportunities for intellectual growth impacted by
social class
Piaget’s formal operational stage
Neo-piagetian postformal stage
Psychosocial
• Mid-life crisis occurs in a small minority of cases,
because most men and women experience gradual
transitions in sense of self and in relationship with
the world
• Personality traits tend to remain stable
• Friendship and marriage/partnership continue as
primary sources of affiliation
• Marital satisfaction often rises as children move
away from home
• Maintenance phase in career may allow for greatest
productivity at work, may also cause burn-out
• Experiences of facing age discrimination more likely
Erikson’s generativity vs stagnation

9. Late Adulthood: Ages 65 - Onward
Biological
• Brain becomes physically smaller and functions
more slowly
• Gradual changes continue in appearance, along with
weakening of the body sense organs and major
body systems
• Losses continue in visual and hearing abilities
• Decreases in immune system and overall muscle
strength put older adults at risk of chronic and
acute illness
• Short-term memory may decline, but active
exercise of mental abilities helps to maintain
functioning
• Age-related changes impact sexual functioning, but
not pleasure
Cognitive
• Abilities to receive information, store it in memory,
and organize and interpret it decline
• Some short-term memory abilities declined, but
methods can help compensate for memory loss and
slower thinking
• Aesthetic, philosophical, or spiritual interests
emerge or intensify
• Language abilities based on memory and processing
speed decline, but overall vocabulary continues to
grow
• Driving-related abilities dependent on information-
processing speed decrease, while skills based on
experience increase
• Wisdom, experience-based problem solving, and
semantic knowledge increase. Older adults cognitive
theories (Levinson, Neugarten)
Psychosocial
• Retirement experience shaped by social class and
gender factors, including income, health, and
amount of previous planning
• Abilities to cope with stress, reduce negative
emotions, and manage personal relationships
improve broader perspective on life
• Subjective sense of well-being tends to be higher
than at all previous periods
• Satisfaction with life largely dependent on family
involvement
• Bereavement for spouse, friends, and families
stressful, but most people are able to integrate a
loss into their lives within one year after it happens

10. • End-of-life care that incorporates pain management
and psychological support greatly impacts well-
being
Erikson’s Integrity vs Despair.