Home / Courses / Developmental Psychology / Unit 8

Developmental Psychology Unit 8: Early and Middle Adulthood

Adulthood from about 18 to 65 brings peak physical functioning followed by gradual change, new ways of thinking, and the major tasks of love, work and caring for others. This unit covers emerging adulthood, physical and cognitive change, relationships, family life, careers and personality.

Covers: Emerging adulthood, Physical change and health, Adult thinking and intelligence, Love and intimate relationships, Marriage, parenthood and family life, Midlife, careers and personality

Study guide

Jeffrey Arnett proposed emerging adulthood (about 18 to 25) as a distinct period in industrialized societies, marked by identity exploration, instability, self-focus, feeling in between adolescence and adulthood, and a sense of possibilities. Physically, strength, reaction time and organ function peak in the 20s and decline slowly after. In middle adulthood, presbyopia (difficulty focusing on near objects) commonly appears in the 40s, hearing for high frequencies declines, metabolism slows and weight often rises. Women go through the climacteric, the transition out of reproductive capacity, ending in menopause, defined as 12 months without a menstrual period, at an average age of about 51. Men experience a gradual decline in testosterone but no equivalent abrupt change. Health habits such as exercise, not smoking and moderate drinking strongly shape how adults age.

Researchers have proposed postformal thought, a stage beyond Piaget's formal operations, in which adults accept that knowledge can be relative, see contradictions as part of life, and combine logic with emotion and practical concerns. William Perry found that college students move from dualistic thinking (right or wrong answers) to relativistic thinking and then to commitment within relativism. Raymond Cattell and John Horn distinguished fluid intelligence, the ability to solve new problems quickly, which peaks in early adulthood and then declines, from crystallized intelligence, accumulated knowledge and vocabulary, which rises into middle and late adulthood. K. Warner Schaie's Seattle Longitudinal Study, which used a sequential design, found that most mental abilities hold steady or peak in middle age, while cross-sectional studies had exaggerated declines because of cohort effects. Expertise also grows through years of practice.

Erikson's young adult crisis is intimacy versus isolation, the capacity to form close, committed relationships, and his middle adult crisis is generativity versus stagnation, the need to guide the next generation through parenting, mentoring or meaningful work. Robert Sternberg's triangular theory describes love as combinations of intimacy, passion and commitment: romantic love has intimacy and passion, companionate love has intimacy and commitment, fatuous love has passion and commitment, and consummate love has all three. Hazan and Shaver found that adult romantic attachment styles resemble infant patterns: secure, anxious and avoidant. John Gottman's research found that stable couples have about five positive interactions for every negative one and that criticism, contempt, defensiveness and stonewalling, his 'four horsemen', predict divorce, with contempt the strongest predictor.

Family life shows several common patterns. Marital satisfaction often dips after the birth of a first child as stress rises and time together falls, and it often rises again after children leave home; the empty nest is more often a relief than a crisis. Many middle-aged adults belong to the sandwich generation, caring for both children and aging parents. Daniel Levinson described seasons of adult life and a midlife transition, but research gives little support to a universal midlife crisis; only a minority report one, usually after specific life events. In careers, Donald Super described stages from exploration and establishment to maintenance and disengagement. Work-family conflict is a major stressor, especially when jobs offer little flexibility, while meaningful work supports well-being and generativity.

Personality shows both stability and change. Paul Costa and Robert McCrae found that the Big Five traits, openness, conscientiousness, extraversion, agreeableness and neuroticism (remembered as OCEAN), are fairly stable in rank order after about age 30. At the same time, the maturity principle describes average changes: conscientiousness and agreeableness tend to rise and neuroticism tends to fall across adulthood. Social roles such as committed relationships and stable jobs encourage these changes, a view called social investment theory. Subjective well-being tends to stay fairly stable or even improve in middle age for many people. Laura Carstensen's socioemotional selectivity theory, covered more fully in late adulthood, already begins to apply as adults focus on fewer but closer relationships.

Key ideas

• Emerging adulthood is a period of exploration and instability between adolescence and settled adulthood.
• Physical functioning peaks in the 20s, and menopause occurs at about 51 on average.
• Fluid intelligence declines from early adulthood, while crystallized intelligence keeps growing into later life.
• Schaie's sequential data showed that cross-sectional studies exaggerate intellectual decline because of cohort effects.
• Sternberg's triangular theory defines types of love by combinations of intimacy, passion and commitment.
• Gottman found that contempt and a low ratio of positive to negative interactions predict divorce.
• Big Five traits are stable in rank order, but conscientiousness and agreeableness rise and neuroticism falls on average.

Formulas and rules

Common mistakes

• Assuming the midlife crisis is a universal stage; research finds it in only a minority of adults.
• Mixing up fluid intelligence (new problem solving) and crystallized intelligence (accumulated knowledge).
• Calling love with intimacy and commitment but no passion 'romantic' rather than companionate.
• Thinking the empty nest usually causes depression; satisfaction often rises when children leave.
• Treating rank-order stability of personality as meaning that average trait levels never change.

Before the test, make sure you can

• Describe the features of emerging adulthood.
• Identify the main physical changes of early and middle adulthood, including menopause.
• Distinguish fluid from crystallized intelligence and describe their life-course patterns.
• Explain why Schaie's sequential findings differ from cross-sectional results.
• Classify types of love using Sternberg's triangular theory.
• Apply Gottman's research on relationship stability.
• Evaluate the evidence on the midlife crisis and the empty nest.
• Describe stability and change in Big Five personality traits.

Words to know

Emerging adulthood

Arnett's term for the period from about 18 to 25, marked by exploration and instability.

Presbyopia

Age-related difficulty focusing on close objects, usually beginning in the 40s.

Climacteric

The midlife transition in which fertility declines.

Menopause

The end of menstruation, confirmed after 12 months without a period, at an average age of about 51.

Postformal thought

Adult thinking that accepts relativity, contradiction and practical limits on logic.

Fluid intelligence

The ability to reason quickly and solve new problems, which declines from early adulthood.

Crystallized intelligence

Accumulated knowledge and verbal skill, which keeps increasing into later adulthood.

Seattle Longitudinal Study

Schaie's sequential study showing that most mental abilities stay stable until about the 60s.

Intimacy vs. isolation

Erikson's young adult crisis about forming close, committed relationships.

Generativity vs. stagnation

Erikson's midlife crisis about contributing to the next generation.

Triangular theory of love

Sternberg's model in which love is made of intimacy, passion and commitment.

Companionate love

Love with intimacy and commitment but little passion.

Consummate love

Sternberg's complete love, combining intimacy, passion and commitment.

Four horsemen

Gottman's four destructive behaviors in couples: criticism, contempt, defensiveness and stonewalling.

Sandwich generation

Middle-aged adults caring for both their children and their aging parents.

Big Five

Five broad personality traits: openness, conscientiousness, extraversion, agreeableness and neuroticism.

Maturity principle

The tendency for people to become more conscientious and agreeable and less neurotic with age.

Sample practice questions

30 more questions like these, from level 1 to 5, are in the practice set.