Zeitgebers are external cues that help maintain circadian rhythms by synchronising the activity of the body’s organs and glands.
Zeitgeist refers to the ideas, trends and values that are dominant in a culture at a particular point in history.
Zone of proximal development the distance between a child's current abilities (when working unaided) and their potential abilities or what are able to achieve under expert guidance.
Psychologyintro
Psychology Glossary Z
Psychology Quote
A civilization which leaves so large a number of its participants unsatisfied and drives them into revolt neither has nor deserves the prospect of a lasting existence.
Sigmund Freud