LCSW Clinical

Prenatal Development and Infancy

Period	Timing	KeyEvents
Germinal	Firsttwoweeks	Celldivisionandimplantation
Embryonic	Weeks3–8	Majororganformation;teratogensposethegreatestrisk
Fetal	Week9tobirth	Growthandrefinement;thebraindevelopsrapidlyinthethirdtrimester

Teratogens include alcohol (fetal alcohol spectrum disorders), tobacco (low birth weight, prematurity), illicit drugs (neonatal abstinence syndrome), certain medications, and infections (TORCH: toxoplasmosis, other, rubella, cytomegalovirus, herpes). Effects depend on timing, dose, and genetic susceptibility.

Neonatal assessment includes Apgar scores (appearance, pulse, grimace, activity, respiration) at 1 and 5 minutes after birth. Reflexes present at birth include rooting, sucking, Moro (startle), grasping, stepping, and Babinski; absence or persistence of reflexes may indicate neurological problems.

Infant development proceeds cephalocaudally (head to toe) and proximodistally (center to periphery). Cognitive development involves increasing attention, memory, and intentional behavior.

Milestone	TypicalAge
Headcontrol	2–4months
Sitting Crawling Walking	6–8months 8–10months 12–14months	1

Early Childhood (Ages 2–6)

Physical: slower growth, improved motor coordination, and brain maturation that supports self-regulation. Fine motor skills develop for drawing, cutting, and dressing; gross motor skills allow running, jumping, and climbing. Cognitive: preoperational thinking characterized by symbolic representation, egocentrism, animism, and magical thinking. Language expands rapidly from two-word combinations to complex sentences, and theory of mind (understanding that others have different thoughts and beliefs) emerges around age 4. Social-emotional: self-concept and self-esteem develop, gender identity typically consolidates, and play progresses from parallel to associative to cooperative. Emotional regulation improves but remains limited, and prosocial behavior and empathy develop.

Middle Childhood (Ages 6–12)

Physical: steady growth, loss of primary teeth, improved coordination, and more organized sports and physical activity; health issues may include obesity, asthma, and attention problems. Cognitive: concrete operational thinking with conservation, classification, and seriation; reading, writing, and math skills develop, metacognition improves, and academic self-concept forms. Social: peer relationships and friendship become central. Industry versus inferiority is the central psychosocial task. Family remains important, but peer influence increases, moral reasoning advances to conventional levels, and self-concept becomes more realistic and differentiated.

Adolescence (Ages 12–18)

Physical: puberty brings hormonal changes, growth spurts, and sexual maturation. Primary sex characteristics involve the reproductive organs; secondary sex characteristics include breast development, voice changes, and body hair. Brain development continues, particularly in the prefrontal cortex, which governs executive functions. Cognitive: formal operational thinking brings abstract reasoning, hypothetical thinking, and idealism. Adolescent egocentrism includes the imaginary audience (the belief that others are constantly observing) and the personal fable (the belief in one's uniqueness and invulnerability).

Identity formation is the central psychosocial task. James Marcia identified four identity statuses, defined by whether the adolescent has explored options and whether he or she has made a commitment. Identity develops across domains including occupation, ideology, relationships, and sexuality.

Marcia'Sidentitystatuses

Commitment Made

No Commitment

Achievement

Moratorium

Exploration

Commitment following exploration

Active exploration, not yet committed

Foreclosure

Diffusion

Exploration

Commitment without exploration

No commitment and no exploration

Risk behaviors peak in adolescence, including substance use, risky sexual behavior, and reckless driving, and peer influence is substantial. Mental health concerns include depression, anxiety, eating disorders, and suicidality. Protective factors include family connectedness, school engagement, and future orientation.

Young Adulthood (Ages 18–40)

Physical: physical development peaks in the twenties and then gradually declines; reproductive capacity is optimal, and lifestyle choices significantly affect health outcomes. Cognitive:postformal thinking is characterized by acceptance of contradiction, integration of emotion and logic, and relativistic thinking. Expertise develops in specific domains; crystallized intelligence increases while fluid intelligence begins to decline. Psychosocial: intimacy versus isolation is the central task; romantic relationships, marriage, family formation, and career establishment are common. Emerging adulthood (ages 18–25) is a distinct period characterized by identity exploration, instability, self-focus, feeling in- between, and possibility.

Middle Adulthood (Ages 40–65)

Physical: declining sensory acuity, graying hair, menopause in women, and decreased muscle mass and bone density; chronic diseases become more common, and regular exercise and a healthy diet become increasingly important. Cognitive: continued growth in crystallized intelligence and expertise; processing speed and working memory may decline, and middle-aged adults often demonstrate practical intelligence and wisdom. Psychosocial: generativity versus stagnation is the central task, as adults contribute to younger generations through parenting, mentoring, and community involvement. The sandwich generation may care for children and aging parents at the same time. Career changes and reassessment are common, but the midlife crisis concept has been largely debunked; most people experience gradual transitions.

Late Adulthood (Ages 65+)

Physical: sensory decline, reduced mobility, chronic health conditions, and cognitive changes. Successful aging involves maintaining physical activity, cognitive engagement, and social connections. The young-old (65–74), old-old (75–84), and oldest-old (85+) show increasing heterogeneity. Cognitive: changes may reflect normal age-related decline in processing speed and memory retrieval or pathological conditions such as mild cognitive impairment or dementia. Alzheimer's disease is the most common type of dementia, characterized by progressive memory loss, confusion, and personality changes.

Psychosocial: ego integrity versus despair involves reviewing one's life and finding meaning and satisfaction; successful resolution brings wisdom. Retirement adaptation varies with health, finances, and social connections. Bereavement becomes common, and end-of-life issues include advance directives, hospice care, and preparation for death.