Chapter 2 - Biological Foundations Flashcards
2.1 Describe the functions of the hormones in the feedback loop of the endocrine system and how they initiate puberty.
The hormonal changes that trigger puberty begin in the hypothalamus, based on a threshold level of leptin. The pathway runs from the hypothalamus to the pituitary gland, to the gonads and adrenal glands, and back to the hypothalamus. The set point for estrogens and androgens increases during puberty.
2.2 Explain how the growth spurt differs for girls and boys, and identify the order in which body parts experience rapid growth.
Girls reach their growth spurt an average of two years earlier than boys but boys have a higher maximum growth velocity. The extremities (hands and feet) see rapid growth first, followed by arms, legs and the head, and then finally the torso.
2.3 Explain the difference between primary and secondary sex characteristics.
Primary sex characteristics are those directly related to the ability to conceive (ovulation and menstruation for girls and sperm production for boys), while secondary sex characteristics are all other pubertal changes, such as growth of pubic hair.
2.4 Provide the typical order of development of secondary sex characteristics in boys and girls.
The first secondary sex characteristic is usually growth of pubic hair, along with early breast development in girls. The last change is increased activity of sweat and oil glands. The order of secondary sex characteristic development is highly predictable, but the age range of each characteristic’s development varies greatly.
2.5 Chart the typical order of pubertal events, and explain the basis for variations in their order, timing, and total duration.
The order of pubertal changes is quite consistent, but the timing and duration are highly variable. In developed countries, early pubertal changes happen in girls as early as 8 or 9 and as late as 13 (generally two years later in boys). The total duration of ‘puberty’ can be from 1.5 to 6 years.
2.6 Describe how physical functioning changes during puberty, and contrast physical functioning in adolescence and emerging adulthood.
Heart and lung capacity increase greatly during adolescence, especially in boys. The same is true of muscle mass. Body fat increases, especially in girls. Emerging adulthood is generally the peak of physical performance, as well as the low point of health risks (other than risks related to behaviours such as accidental death, death from substance abuse, etc.)
2.7 Explain how culture influences the timing of puberty.
Because technology, including nutrition and medical care, is considered part of culture, we can consider the culture of developed countries to have the effect of lowering the average age of puberty.
2.8 Identify the rates of prevalence of puberty rituals across cultures, and explain the function of these rituals.
Puberty rituals are extremely common in traditional cultures (less so in the West), and function to recognize entry into adulthood - particular menarche in girls and tests of strength and endurance in boys.
2.9 Compare and contrast cultures in how puberty influences family relations.
In majority American culture, puberty usually involves some amount of distancing between parents and children, but this effect is not seen as much in traditional cultures. In fact, parent-child relationships may involve more closeness after puberty in traditional cultures, as the adolescents spend time working with their parents.
2.10 Describe personal responses to menarche and semenarche among adolescents and how these responses are shaped by cultures.
The major effect of culture on response to puberty is the negative correlation between amount of information provided to children before puberty and the level of trauma in their response to menarche/semenarche.
2.11 Summarize the gender differences in how boys and girls respond to reaching puberty relatively early or late.
For boys, late maturation is more problematic than early maturation as they may be at a disadvantage in socially valued activities such as sports that are age-grouped. For girls, early maturation can be more problematic as it correlates with risky behaviours including drug use.
2.12 Compare and contrast passive, evocative, and active genotype → environment effects.
Passive genotype > environmental effects occur for those who are raised by biological parents, as the genetics and environment are both provided by the same people. Evocative genotype > environment effects result when others treat the individual differently based on their traits, for example when introverted children are given more books to read. Active genotype > environment effects refer to choices made by the individual to seek out an environment most suited for their traits, for example when someone who is tall joins a basketball team.
2.13 Explain why genotype → environment effects change over time.
As adolescents become more capable of choosing their environment, passive genotype > environment effects decline and active genotype > environment effects rise in prominence.
