Chapter Seventeen

Early Adulthood:Biosocial Development

Dr. M. Davis Brantley

• Young adults are strong, healthy, and disease free

• Men typically stronger than women• For both sexes, physical strength

increases until 30, then declines• All body systems functioning at

optimum levels• Death from disease is rare

– violent death more likely

Norms and Peaks

• Occurs when growth stops but ongoing throughout adulthood

• Physical decline related to age– varies markedly from person to

person, organ to organ

• Organs: First visible changes are in skin--looses elasticity

• Graying hair and male pattern baldness begin around age 30

• Variability in senescence appears

Signs of Senescence

Gender Differences in Health and Senescence

• Appearance seems more important for women than for men– in some ways, women slower to become old– women generally healthier and have better

health habits• few fatal diseases, live at least 5 years longer

than men, on average

• Two ways females are at a health disadvantage– undernourishment– reproductive systems problems

Gender Differences in Health and Senescence

• Three explanations why twice as many women than men live to after age 80– biological: protective evolutionary

biology– cognitive: less risk taking– psychosocial: marriage, family life,

friendship, and help-seeking are all protective of health, and women are more likely to engage in these

• Body’s attempt to keep systems in balance —homeostasis– set point is affected by genes, diet,

age, hormones, and exercise

• Aging makes it more difficult to recover from physical stress

• What a 20-year-old can do is more difficult for a 35-year-old

Homeostasis

Sexual Responsiveness

• Typical male sexual response – sexual arousal and excitement– orgasm– refractory period (time between responses)

is short– overall slowing down over time

• Typical female sexual response– sexual arousal and excitement and orgasm

take longer than for men– from early adolescence to middle

adulthood, arousal and orgasm become more likely

Sexual Responsiveness, cont.

• Explanations of differences in sexual responsiveness, cont.– evolutionary psychology

• promiscuous males produce more offspring and pass on their genes more often, which is an evolutionary goal

• women reproduce and create safe haven for children

• Peak time of fertility for women: before age 30; for men: before age 40

• Between 2 percent and 30 percent of all couples experience infertility—average of 15 percent– infertility—failure to conceive after a

year of intercourse without contraception

Fertility

Fertility, cont.

• Male Infertility– 1/4 of cases related to sperm/sperm

count

• Female Infertility– pelvic inflammatory disease may

block fallopian tubes – endometriosis– infections, fibroid tumors

• uterine health affected by other health factors

Fertility, cont.

• Medical Advances – in vitro fertilization (IVF)—ova

surgically removed, fertilized by sperm in lab, and allowed to divide until zygote reaches 8- or 16-cell stage

– assisted reproductive technology (ART)— collective name of different technologies that aid in fertility

Emotional Problems in Early Adulthood

• Dieting, Drugs, Violence

• Set point—particular body weight that an individual’s homeostatic process strives to maintain

• Dieting is common among girls, not unusual for boys

• One in 20 teenagers takes dieting too seriously and has an eating disorder

Dieting as a Disease

Dieting as a Disease, cont.

• Culture and diet industry messages (via media) tell us to be thin so we will be happy and successful– almost 50 percent of women in North

America have a BMI of less than 25, so they are not overweight at all

– many young women connect self-concept with body image

Anorexia Nervosa

• Restriction of eating to the point of emaciation and possible starvation

• Four Symptoms– refusal to maintain body weight of at

least 85 percent of normal weight for age and height

– intense fear of gaining weight– disturbed body perception and denial

of problem– in females, absence of menstruation

Bulimia Nervosa

• Repeated episodic binge eating followed by purging

• To be clinically diagnosed, – bingeing and purging must occur at

least once a week for three months – the person must have uncontrollable

urges to overeat – the person must show distorted self-

judgment about body image

Drug Abuse and Addiction

• Marked gender, ethnic, and national variations in rates of drug addiction– men more likely than women– European Americans and Hispanic

Americans more likely to use than are Asian-Americans or African Americans

– English-speaking countries more likely to use drugs

Drug Abuse and Addiction, cont.

• College students particularly vulnerable– more to alcohol

• Social context encourages use and abuse– on their own– spectator sports– other group activities

Drug Abuse and Addiction, cont.

• Consequences of drug use often serious– avoid, drop out of, or flunk out of college– work below potential– lose or quit jobs– involved in transitory, uncommitted sexual

relations– die violently– experience serious psychological difficulties

• Many young adults struggle with serious emotional difficulties– 12 percent experience at least one episode of

• depression, schizophrenia, or pathological rage• made worse if using drugs or alcohol

• Some difficulties may originate in childhood– parents abusive, neglectful, or erratic– death of mother or alcoholism of father

• Typically, childhood disturbances, biological problems, and environmental stress are all involved

Psychopathology

• Between ages 20 and 35, at least 15 percent of women and 8 percent of men suffer from at least one severe episode of depression

• Major depression is fueled biochemically– neurotransmitters– hormones

• Remission is likely with treatment that includes cognitive therapy and medication

Depression

• 1 percent of all adults experience at least one episode of schizophrenia

• Caused by genes and severe early trauma such as anoxia at birth

• Medication seems to be most effective if person understands disease

Schizophrenia

Violence

• In U.S., 1 male in every 100 between the ages of 15 and 25 dies violently– motor vehicle accident, homicide, or

suicide

• Worldwide, young men more likely to die violently than women (especially between ages of 20 and 25)– 4 times as many commit suicide– 6 times as many are murdered– by nation or ethnic group, male-to-

female ratio varies from 3:1 to 10:1

Violence, cont.

• Developmentalists suggest two reasons– biological—unlike females, in males,

higher levels of testosterone correlate with impulsive, angry reactions

– psychological—high self-esteem and dashed expectations more likely to result in violence in the presence of alcohol, a weapon, or lack of self-restraint