a complex behavior that is rigidly patterned throughout a species and is unlearned.
a need or desire that energizes and directs behavior.
the idea that a physiological need creates an aroused tension state (a drive) that motivates an organism to satisfy the need.
a tendency to maintain a balanced or constant internal state; the regulation of any aspect of body chemistry, such as blood glucose, around a particular level.
a positive or negative environmental stimulus that motivates behavior.
hierarchy of needs
Maslow's pyramid of human needs, beginning at the base with physiological needs that must first be satisfied before higher-level safety needs and then psychological needs become active.
the form of sugar that circulates in the blood and provides the major source of energy for body tissues. When its level is low, we feel hunger.
basal metabolic rate
the body's resting rate of energy expenditure.
the point at which an individual's "weight thermostat" is supposedly set. When the body falls below this weight, an increase in hunger and a lowered metabolic rate may act to restore the lost weight.
an eating disorder in which a normal-weight person (usually an adolescent female) diets and becomes significantly (15 percent or more) underweight, yet, still feeling fat, continues to starve.
an eating disorder characterized by episodes of overeating, usually of high-calorie foods, followed by vomiting, laxative use, fasting, or excessive exercise.
sexual response cycle
the four stages of sexual responding described by Masters and Johnson—excitement, plateau, orgasm, and resolution.
a sex hormone, secreted in greater amounts by females than by males. In nonhuman female mammals, estrogen levels peak during ovulation, promoting sexual receptivity.
a resting period after orgasm, during which a man cannot achieve another orgasm.
a problem that consistently impairs sexual arousal or functioning.
the most important of the male sex hormones. Both males and females have it, but the additional testosterone in males stimulates the growth of the male sex organs in the fetus and the development of the male sex characteristics during puberty.