- Tourette Syndrome
- Traits
- Transference
- Transgender
- Twins
- Type a Personality
- Unconscious
- Unconscious Motivation
- Underachiever
- Viktor E. Frankl
- Violence
- Virginia E. Johnson
- Virginia M. Satir
- Vision
- Visual Angle
- Vocational Aptitude Test
- Waldo David Frank
- Wechsler Intelligence Scales
- Wilder Graves Penfield
- Wilhelm Max Wundt
- Wilhelm Reich
- William Herbert Sheldon
- William James
- William Masters
- William Mcdougall
- Withdrawal Behavior
- Wolfgang Köhler
- Word Association Test
