Adolescence - Puberty, Health, and Biological Foundations

What is puberty?

Brain-neuroendocrine process in early adolescence that stimulates rapid physical changes.

What is the role of sex hormones in puberty for males and females?

In males, rising testosterone levels lead to the development of external genitals, increased height, voice changes, and sexual desire. In females, rising estradiol levels lead to breast and uterine development and skeletal changes. Hormonal contributions to sexual desire are less clear in girls than in boys.

Explain the negative feedback system involved in managing the levels of sex hormones.

High sex hormone levels decrease hypothalamus and pituitary gland stimulation of gonads, reducing sex hormone production. In males, low testosterone levels cause the hypothalamus to produce more GnRH, restarting the cycle. A similar system operates in females, with LH and GnRH regulating ovaries and estrogen production.

What could happen if a prepubescent girl's total body fat percentage was lower than average?

Menarche is influenced by the percentage of body fat. Anorexic adolescents and female athletes may not menstruate, suggesting delayed or absent menstruation with very low body fat.

Compare and contrast the growth spurt experience in boys and girls. Could you be sure to include ages and bodily changes?

The growth spurt occurs approximately 2 years earlier for girls (age 9) than boys (age 11) on average. The peak of pubertal change occurs at 11½ years for girls and 13½ years for boys. Girls increase in height by about 3½ inches per year; boys, by about 4 inches. Girls' growth spurt typically begins before menarche and ends earlier, while boys' begins later and ends later. At the beginning of adolescence, girls tend to be as tall as or taller than boys; by the end of middle school, boys catch up, and many surpass girls in height.

List in order the male and female pubertal changes.

Males: 1. Increased penis and testicle size, 2. Appearance of straight pubic hair, 3. Minor voice change, 4. First ejaculation (spermarche), 5. Appearance of kinky pubic hair, 6. Onset of maximum growth, 7. Growth of armpit hair, 8. More detectable voice changes, 9. Growth of facial hair. Females: 1. Breast development, 2. Growth of pubic hair, 3. Growth of armpit hair, 4. Height gain, 5. Hips become wider than shoulders, 6. First menstruation (menarche).

Define the term "precocious puberty."

Very early onset and rapid progression of puberty, occurring before the age of 8 in girls and before the age of 9 in boys.

Compare and contrast changes in body image that occur at puberty for males and females.

In general, throughout puberty, girls are less happy with their bodies and have more negative body images than boys. As pubertal change proceeds, girls often become more dissatisfied with their bodies, probably because their body fat increases. In contrast, boys become more satisfied as they move through puberty, probably because their muscle mass increases.

Discuss some advantages and disadvantages of early and late maturation.

Early maturation in girls increases vulnerability to problems, including substance use, depression, and earlier sexual experiences. Early maturation often has more favorable outcomes in adolescence for boys, especially in early adolescence. Later in life, however, boys’ late maturation may be more favorable, especially in terms of identity and career development.

What are some of the problems of risk-taking behavior in adolescence?

The development of the prefrontal cortex combined with the earlier maturity of the amygdala may explain the difficulty younger adolescents have in putting the brakes on their risk-taking adventures. Consequences can include unintentional injuries (e.g., motor vehicle accidents), substance abuse, and risky sexual behavior.

Adolescents need to utilize the services of private physicians and other healthcare services. List and briefly explain at least four barriers to better adolescent health care.

1. Cost: Many adolescents lack adequate health insurance. 2. Poor organization and availability of health services: Health care services may not be easily accessible or conveniently located for adolescents. 3. Lack of confidentiality: Adolescents may be concerned about privacy. 4. Reluctance on the part of health care providers to communicate with adolescents about sensitive health issues: Healthcare providers may lack training or time to address sensitive issues effectively.

Describe the concerns raised about adolescents' nutritional status and diets in the United States today.

Concerns include the amount of fat in the diet and the increase in consumption of energy drinks, which tend to have high caffeine levels. Eating regular family meals during early adolescence is linked to healthy eating habits 5 years later.

What steps would you take if you wanted to increase the activity levels of adolescents?

Encourage feeling safe, provide a number of places to be active, and have parents who participate in physical activities with them. Schools can also play an important role in adolescents’ eating patterns.

What has research found about the amount of sleep adolescents need, the amount of sleep they usually get, and the problems associated with lack of adequate sleep?

Only 25\% of U.S. adolescents get 8 or more hours of sleep on an average school night. Lack of sleep is linked to academic deficiencies, less efficient information processing, and a greater incidence of emotional, mood, and substance abuse problems, and poorer relationships with peers.

What are some of the main themes in evolutionary psychology? Could you give an example of human behavior that evolutionary psychologists study?

Evolutionary psychology emphasizes the importance of adaptation, reproduction, and 'survival of the fittest' in explaining behavior. An example is the extended childhood period evolved because humans require time to develop a large brain and learn the complexity of human societies.

Define the terms genotype and phenotype.

A person’s genetic heritage—the actual genetic material—is called a genotype. The way an individual’s genotype is expressed in observed and measurable characteristics is called a phenotype.

Explain twin studies

Twin study: Behavioral similarities of identical twins are compared with that of fraternal twins to determine the influence of genetics. Identical twins are monozygotic twins, while fraternal twins are dizygotic twins

Explain adoption studies

Adoption studies aim to discover whether the behavior and psychological characteristics of adopted children are more like those of their adoptive parents or those of their biological parents. They are used to assess the relative contributions of heredity and environment on development.

Sandra Scarr - heredity and environment related

Passive genotype-environment correlations occur because biological parents provide the rearing environment. Evocative genotype-environment correlations occur because an individual’s genetically shaped characteristics elicit certain types of physical and social environments. Active (niche-picking) genotype-environment correlations occur when children seek out environments they find compatible and stimulating.