U fiber U test U-shaped distribution U.S. Department of Veterans Affairs (VA) U.S. Drug Enforcement Administration (DEA) U.S. Food and Drug Administration (FDA) UCLA Loneliness Scale UCR UCR fees Ucs UCS UG ulcer Ullrich–Noonan syndrome ulnar nerve ultimate attribution error ultimate cause ultimate explanation ultimate opinion testimony ultimatum game Ultiva ultradian rhythm ultrasonic communication ultrasonic irradiation ultrasound ultraviolet (UV) ululation umami umbilical cord UMP test Umweg problem Umwelt unaspirated sound unattended input unbalanced bilingual unbalanced design unbiased unbiased estimator unbiased sampling uncal herniation uncertainty uncertainty analysis uncertainty avoidance uncertainty factor uncertainty orientation uncertainty principle uncertainty reduction theory (URT) uncertainty-arousal factor uncinate fasciculus unconditional positive regard unconditioned reflex unconditioned reinforcement unconditioned reinforcer unconditioned response (UCR; UR) unconditioned stimulus (UCS; US) unconditioned stimulus devaluation (US devaluation) unconditioned stimulus preexposure effect (US preexposure effect) unconscious (Ucs) unconscious cognition unconscious context unconscious homosexuality unconscious inference theory unconscious intention unconscious knowledge unconscious learning unconscious motivation unconscious perception unconscious plagiarism unconscious process unconscious resistance unconscious transfer uncontrollable turnover uncontrolled variable unconventional therapy uncovering uncriticalness uncrossed disparity uncued panic attack uncus underachiever underage underclass underconfidence underconfidence-with-practice effect underdog underextension underidentification underintensity underload underlying distribution undermatching underpayment inequity undershoot understaffing understanding undescended testicle undifferentiated schizophrenia undifferentiated somatoform disorder undue hardship undulatio reflexa unexpected panic attack unexplained variance unfair labor practices unfalsifiable unfinished business unfinished story unfitness unfolding unidimensionality unified positivism unified theory of cognition Unified Tri-Service Cognitive Performance Assessment Battery (UTCPAB) Uniform Crime Reports uniform distribution Uniform Guidelines for Employee Selection Procedures uniformly most powerful test (UMP test) unilateral unilateral couple counseling unilateral descent unilateral lesion unilateral neglect unilineal descent unimodal distribution unimodel of persuasion uniocular union union shop uniparous unipolar disorder unipolar mania unipolar neuron unipolar rating scale unipolar stimulation unique hue unique trait uniqueness Unit Manning System unit normal distribution unit normal variable unit of analysis unit schedule unitary-resource model United Nations Declaration on the Rights of Mentally Retarded Persons unity unity in variety unity of command unity of consciousness unity of science univariate univariate analysis univariate distribution univariate research universal universal design universal grammar (UG) universalism universality universality of emotions universalizability universals universe universe of discourse University of Pennsylvania Smell Identification Test (UPSIT) unlearning unmyelinated unnumbered graphic rating scale unobtrusive measure unplanned comparison unpleasantness unpleasure unprepared learning unresolved unrestricted model unsaturated model unshared environment unsociable unspecified mental retardation unstandardized score unstructured unstructured autobiography unstructured interview unstructured stimulus unsystematic variance unthought known Unusual Uses Test unvoiced unweighted means analysis up through up-and-down method up-regulation upper upper hinge upper motor neuron upper quartile upper real limit upper threshold UPSIT upward appraisal upward communication upward grade homogenization upward mobility upward Pygmalion effect upward social comparison UR ur- uracil uranoschisis urban behavior urban ecology urban legend Urban’s weights urbanism urbanization Urecholine urethra urethral eroticism urethritis urge incontinence urinary incontinence urination urn model uro- (ur-) urogenital urolagnia URT urticaria US US devaluation US preexposure effect us-versus-them effect usability engineering usable use-and-disuse theory useful field of view user-centered design user-friendly Usher syndrome usual, customary, and reasonable fees (UCR fees) UTCPAB uterine orgasm utero- (uter-) uterus utilitarian function of an attitude utilitarianism utility utility standards utility theory utilization deficiency utilization review (UR) utilization-focused evaluation utopia utopianism utricle utterance UV uveal tract uvula uvular uxoricide uxorilocal