In any given place, at any given time, people are never where they’re supposed to be. A combination of SOD’S LAW and the Heisenberg Uncertainty Principle.

The relationship or DEPENDENCE between two variables.

Feelings of anonymity and being part of a crowd. A blurring of individual IDENTITY and a loosening of INHIBITIONS.

See COLLECTIVE MIND and CONTAGION THEORY OF CROWDS.

The DELUSION that one is a celebrated or exalted person.

How well each item of a psychological test measures or predicts what it’s supposed to measure or predict.

In EXPERIMENTAL PSYCHOLOGY, the distorting effect of uncontrolled facts external to the EXPERIMENT, the most important being the CONSCIOUS or UNCONSCIOUS assumptions of the experimenter.

See EXPERIMENTER BIAS and ROSENTHAL EFFECT.

The branch of PSYCHOLOGY that deals with the interactions of physical, psychological and social changes that occur as an individual increases in age. For a long time, this meant largely CHILD DEVELOPMENT and perhaps adolescence but increasing attention is now being paid to MIDDLESCENCE and SENESCENCE.

Supposed response of an animal or human to the effects of being crowded, and often subject to very dubious GENERALISATION across species.

For example, the aggressive behaviour of rats at a certain level of crowding is thought by many to be INSTINCTIVE and this ‘explanation’ may then be offered to account for violence in urban slums. There is little or no hard evidence that any human behaviour is instinctive, and as an explanation for the extremely complex (and sometimes apparently contradictory) relationship between urban violence and crowding, it is so simplistic as to be silly.

Derived from a Greek term meaning something like ‘steersman’, cybernetics was introduced in 1948 by Norbert Wiener, a computer engineer. It is usually defined briefly as the study of regulatory mechanisms (like thermostats). Out of this field came the analogy of the brain as a computer and the model of psychological processes as systems of messages with their own built-in FEEDBACK.

See JUST NOTICEABLE DIFFERENCE.