Lifespan overheads, chapter 13: physical and cognitive development in early adulthood
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Chapter 13: Physical & Cognitive Development in Early
Adulthood
Physical Development
 senescence begins
o varies widely across parts of the body, and across
people
Life Expectancy: 20th century gains in life expectancy equal
those of the previous 5000 years
 nutrition, medicine, sanitation, safety, infant mortality
 heart disease has dropped by nearly 50% in the last 30
years
leading causes of death:
1) unintentional injuries
2) cancer
3) heart disease
4) suicide
5) AIDS
 women’s lifespans are 4 to 7 years longer
 in industrialized nations, this gap is shortening
Maximum life span:
 some believe 85 or 90 years
 Others say we haven’t yet identified the human genetic
limit to lifespan
o doubled the lifespan of fruit flies
o increased the lifespan of the roundworm by 70%
o raised rodents who live 30% longer
 the active lifespan averages 64 years
 oldest verified age of a person is 122 years
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Theories of aging
Aging at the level of DNA and Body Cells:
Theory 1: specific genes are programmed for the aging
process.
 human cells allowed to divide in the laboratory have a
lifespan of 50 +/- 10 divisions.
 with each duplication, they lose telomeres
 when they replace the telomeres they extend the
lifespan of the cells
Theory 2: cumulative effects of random events that
damage genetic and cellular material.
 there is an increase in DNA breaks and deletions and
other damage with age
 free radicals: genes for longevity may work by
defending against free radicals
Aging at the level of tissues and organs:
 cross-linkage of protein fibers
 a gradual drop in growth hormone (GH) associated with
loss of muscle, addition of body fat, thinning skin
 immune system declines lead to increased risk of
cancer, cardiovascular disease, infections
Physical Changes
 cardiovascular and respiratory:
o Only when people are exercising do we see a
decline in performance with age.
o Atherosclerosis: begins early in life, progresses
in adulthood, and leads to serious problems in
middle to late adulthood.
Lifespan overheads, chapter 13: physical and cognitive development in early adulthood
o Young/middle aged adults at low risk for heart
disease: 40 to 60% reduced death rates
o Lungs: during exertion, respiratory volume
decreases and breathing rate increases with age.
Motor performance: peaks between 20-30, then declines.
 If person remains active, performance drops only 2%
per decade
 older people who participate in sports have twice the
vital capacity as their peers who do not
Immune system:
 T-cells and B-cells
 after age 20 the thymus starts to shrink; compromises
immune response
 stress
Reproductive capacity:
 female fertility declines sharply in the mid-30s (26% of
women 35 to 44 cannot conceive naturally).
 Male fertility declines after 40, as the quantity of sperm
in semen declines.
Health
 overweight and obesity:
o 22% are obese ; 54% are overweight
o 4% of men and 8% of women have large weight
gains between 25 and 34
o between 25 and 50, basal metabolic rate (BMR)
gradually declines
o excessive fat is associated with high blood
pressure, atherosclerosis, diabetes, arthritis,
cancer, early death
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Lifespan overheads, chapter 13: physical and cognitive development in early adulthood
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Exercise: only 23% of Americans engage in moderate
physical activity for 20 minutes or more ate last 3 times a
week.
 exercise fosters resistance to disease
 linked to reduced incidence of cancer
 helps prevent adult-onset diabetes
 reduces risk/severity of cardiovascular disease
 reduces anxiety and depression
 helps handle stress
Substance abuse
 cigarettes: 25% of adult Americans smoke
 smoking in young people at college is on the rise
 average # of cigarettes smoked per day is 20
 the earlier people start, the greater their daily intake
 the greater the daily intake, the greater the chance of
premature death.
 Quitting: return to non-smoker disease-risk in 3-8 years
Alcohol:
 13% of men and 3% of women in the US are heavy
drinkers. 1/3 of these are alcoholics
 men: alcoholism begins in teens/early 20s, worsens
over time
 women: onset is in 20s/30s, more variable outcome
Sexuality
Heterosexuals:
 by 20, 80% have had sexual intercourse; by 22, 90%.
 Americans are far less sexually active than we are led
to believe through media representations.
Lifespan overheads, chapter 13: physical and cognitive development in early adulthood
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50% aged 30-50 have had 5 + partners
71% report only one partner in the past year
3% (mostly men) report 5+ partners in past year
33% of 18-to-59-year-olds have sex twice a week
33% have sex a few times a month
33% have sex a few times a year or not at all
 As number of sex partners increases, satisfaction
declines sharply.
Sexual problems
 for women: lack of interest in sex (33%); inability to
achieve orgasm (24%)
 for men: climaxing too early (29%); anxiety about
performance (16%)
Homosexuals
 2.8% of men, 1.4% of women are homosexual/bisexual
 most Americans support equal job opportunities for gay
men, lesbians, and bisexuals.
 heterosexual men judge homosexual men more harshly
 tend to be more educated than the general population,
Sexual coercion:
 14 to 25% of women have been victimized by rape
Most (80%) are under age 30.
 Most knew their attacker well.
 44% of college women reported sexual coercion; 19%
of college men said they had gotten sex through force
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 Men who engage in sexual assault:
o believe in traditional gender roles
o accept rape myths
o have a desire to dominate their victims
o claim that “she brought it on herself”
o have trouble interpreting women’s social behavior
 strong gender stereotyping contributes to sexual
coercion
 acceptance of violence in our culture also contributes
 women’s psychological reactions resemble those of
survivors of extreme trauma
 1/3 to ½ of rape victims are physically injured; 5% get
pregnant
Menstruation
 PMS: Usually experienced for the 1st time after age 20.
40% of women have some variant of symptoms.
Psychological stress: mobilizes the body for action; can
affect immune functioning; linked to several kinds of cancer,
gastrointestinal problems
Cognitive development
 Perry’s theory: college students’ cognitive perspectives
changed as they were exposed to the complexities of
university life and moved closer to adult roles.
o Younger students: knowledge as separate units
 dualistic thinking
o Older students: were aware of a diversity of
opinions on almost any topic
 relativistic thinking
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 Schaie’s theory: there are stages we go through
reflecting our changing goals of mental activity
o
o
o
o
The acquisitive stage
The achieving stage
The responsibility stage
The reintegrative stage
 Labouvie-Vief’s theory: thinking moves from
hypothetical to pragmatic
o become aware of the constraints of everyday life
o learn to accept inconsistencies as part of life
o develop ways of thinking that thrive on
imperfection and compromise
Information processing: expertise and creativity
Expertise:
 remember and reason more quickly and effectively
 they approach problems with underlying principles in
mind, whereas novices approach problems in
superficial ways
 fosters creativity
 creativity rises in early adulthood, peaks in the late 30s
or early 40s, and gradually declines.
 exceptions to this trend: early starters and late
bloomers
College
 “culture shock”
 75% of high school graduates enroll in higher education
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Psychological impact of college:
 applying reason and evidence to problems
 identifying strengths and weaknesses of different sides
of complex issues.
 greater self-understanding, enhanced self-esteem,
firmer sense of identity
 determined by how involved the person gets in
academic and nonacademic activities; and the richness
and diversity of the college setting
o residential living
o extensive contact with faculty
 40% drop out, most within the first year, many within
the first 6 weeks.
Vocational choice
Selecting a vocation:
1. fantasy period (early and middle childhood)
2. tentative period (early/middle adolescence)
3. realistic period (late adolescence, early adult)
Factors influencing vocational choice:
Personality
John Holland (1966):
1) the investigative person
2) the social person
3) the realistic person
4) the artistic person
5) the conventional person
6) the enterprising person
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Family
 people in higher SES homes select higher-status
occupations; those in lower-SES homes select lowerstatus occupations.
 parental pressure to do well and encouragement toward
high-status occupations predict beyond SES
Teachers: 39% of college freshmen rate a high school
teacher as the most important impact on their choice of
field of study.
Gender stereotypes
 while the % of women in “masculine” careers has
increased, it still falls well short of equality.
 women remain heavily concentrated in traditionally
feminine professions
 girls’ grades are overall higher than boys’ in secondary
school, but girls are less confident in their ability and
more likely to underestimate their achievement.
 during college, their career aspirations decline further
 women constitute 9% of engineers and physicists