A term for the study of group behaviour among children, based on the work of Muzafer and Carolyn Sherif, who set up a classic series of natural experiments at summer camps in the 1950s where they identified the strengths and conflicts of a miniature society and set about resolving the conflicts that had been created.

In group membership, the skills manifested by certain members as leaders or experts within the group and whose role is thus more social- than task-related.

A type of play amongst children, involving chasing and tackling each other, which most children by the age of 8 are able to discern from aggressive fighting.

A consistent pattern of motor behaviour in the infant which is based on reflexes, such as sucking or grasping.

(SADD) a term applied to single, simple expressions that are affirmative and declarative, in that they are making positive declarations about something being true and are presented in an active voice.

In self-concept formation, the questions of when we make comparisons, what we compare, and why, as well as with whom comparisons are made; this phenomenon is also applied by the individual in social group processes.

The system of sensory messages that passes from the cerebral cortex to the muscles in the periphery.

The system of receptors in the body that communicates the messages relating to sensation and touch.

In the ontogeny of environmental cognition as described by Piaget, the childs concept of space constructed on topological principles.

The proportion of each incident stimulus wavelength that a surface reflects.

The pattern of response of a neurone to different stimulus wavelengths.