Hallucinations False perceptions that occur in the absence of objective stimulation.
Health A general condition of soundness and vigor of body and mind; not simply the absence of illness or injury.
Health promotion The development and implementation of general strategies and specific tactics to eliminate or reduce the risk that people will become ill.
Health psychology The field of psychology devoted to understanding the ways people stay healthy, the reasons they become ill, and the ways they respond when they become ill.
Heredity The biological transmission of traits from parents to offspring.
Heritability estimate A statistical estimate of the degree of inheritance of a given trait or behavior, assessed by the degree of similarity between individuals who vary in their extent of genetic similarity.
Heuristics Cognitive strategies, or "rules of thumb," often used as shortcuts in solving a complex inferential task.
Hierarchy of needs Maslow's view that basic human motives form a hierarchy and that the needs at each level of the hierarchy must be satisfied before the next level can be achieved; these needs progress from basic biological needs to the need for transcendence.
Hippocampus The part of the limbic system that is involved in the acquisition of explicit memory.
HIV Human immunodeficiency virus a virus that attacks white blood cells (T lymphocytes) in human blood, thereby weakening the functioning of the immune system; HIV causes AIDS.
Homeostasis Constancy or equilibrium of the internal conditions of the body.
Horizontal cells The cells that integrate information across the retina; rather than sending signals toward the brain, horizontal cells connect receptors to each other.
Hormones The chemical messengers, manufactured and secreted by the endocrine glands, that regulate metabolism and influence body growth, mood, and sexual characteristics.
Hozho A Navajo concept referring to harmony, peace of mind, goodness, ideal family relationships, beauty in arts and crafts, and health of body and spirit.
Hue The dimension of color space that captures the qualitative experience of the color of a light.
Human behavior genetics The area of study that evaluates the genetic component of individual differences in behaviors and traits.
Human-potential movement The therapy movement that encompasses all those practices and methods that release the potential of the average human being for greater levels of performance and greater richness of experience.
Humanistic perspective A psychological model that emphasizes an individual's phenomenal world and inherent capacity for making rational choices and developing to maximum potential.
Hypnosis An altered state of awareness characterized by deep relaxation, susceptibility to suggestions, and changes in perception, memory, motivation, and self-control.
Hypnotizability The degree to which an individual is responsive to standardized hypnotic suggestion.
Hypothalamus The brain structure that regulates motivated behavior (such as eating and drinking) and homeostasis.
Hypothesis A tentative and testable explanation of the relationship between two (or more) events or variables; often stated as a prediction that a certain outcome will result from specific conditions.