1) Describe the physiological factors that produce hunger.
Although the stomach's pangs contribute to hunger, variations in body chemistry are more important. Increases in the hormone insulin diminish blood glucose, partly by converting it to stored fat. We do not consciously feel this change in blood chemistry.
Rather, our body's internal state is monitored by areas deep within the hypothalamus (for example, the arcuate nucleus), which regulates the body's weight as it influences our feelings of hunger and fullness. One task of the hypothalamus is to monitor levels of the appetite hormones such as ghrelin (which is secreted by an empty stomach).
Other appetite hormones include leptin, PYY, and orexin. Some researchers have abandoned the idea that the body has a precise set point-a biologically fixed tendency to maintain an optimum weight-preferring the term settling point to indicate an environmentally and biologically influenced level at which weight settles in response to caloric input and expenditure.
Human bodies regulate weight through the control of food intake, energy output, and basal metabolic rate-the body's resting rate of energy expenditure.
2) Discuss the factors that influence teen pregnancy and risk of sexually transmitted infections.
Although physical maturation fosters a sexual dimension to adolescents' emerging identity, sexual expression varies greatly with time and culture. Compared with European teens, American teens have a higher pregnancy rate.
One reason for this high rate is minimum communication about birth control, as many teenagers are uncomfortable discussing contraception with either parents or partners.
Guilt related to sexual activity sometimes results in lack of planned birth control. When passion overwhelms intentions, the result may be conception. Sexually active teens also tend to use alcohol, which can break down normal restraints. Finally, television and movies foster sexual norms of unprotected promiscuity.
Unprotected sex has also led to increased rates of sexually transmitted infections (STIs). Teenage girls, because of their less mature biological development and lower levels of protective anti- bodies, seem especially vulnerable to STIs. Attempts to protect teens through comprehensive sex- education programs include a greater emphasis on teen abstinence.
Teens with high rather than average intelligence more often delay sex. Religiosity, father presence, and participation in service learning programs are also predictors of sexual restraint.
3) Explain the concept of flow, and identify three subfields of industrial-organizational psychology.
Work helps satisfy several levels of Maslow's pyramid of needs. Work supports us, connects us to others, and helps define us. People may view their work as a job, a career, or a calling. When work fully engages our skills, we experience flow.
We are completely involved and have a diminished awareness of self and time. Flow experiences boost our sense of self-esteem, competence, and well-being.
Industrial-organizational (I/O) psychology aims to apply psychology's principles to the work- place through its primary subfields of personnel psychology, organizational psychology, and human factors psychology.
Personnel psychology applies the discipline's methods and principles to selecting and evaluating workers. Organizational psychology considers how work environ- ments and management styles influence worker motivation, satisfaction, and productivity. Human factors psychology explores how machines and environments can be optimally designed to fit human abilities.