APA Dictionary of Psychology

n. a condition of underdeveloped body structure due to a developmental defect, a hereditary trait, hormonal or nutritional deficiencies, or disease. The relative size of the body, head, and limbs may be proportionate or disproportionate. Some forms of dwarfism, such as that due to thyroid-hormone deficiency, are associated with intellectual developmental disorder, but almost all individuals with achondroplastic dwarfism (see achondroplasia) have typical intelligence. See also pseudoachondroplasia; .