(social) Describes some aspect of an individual’s condition such that it becomes a way of defining that individual’s relationship with the rest of the world.

The asymmetrical distribution of function between the two hemispheres of the brain, e.g. localisation of language in the left hemisphere.

A mixture containing opium, which was widely available in Britain in the Victorian period.

The law that states that behaviour is strengthened by its consequences.

The process by which a memory of experience is acquired that will modify behaviour.

A graph showing an index of learning as a function of the number of trials over time.

A term applied to explanations for a certain phenomenon which are derived from a coherent body of concepts, hypotheses and knowledge associated with a particular academic discipline or subdiscipline; the term signifies the existence and value of other levels of explanation of the same phenomenon.

The average number of years a person can expect to live from birth.

The length of life of the longest-lived member of a species.

Cells located at the retina of the eye and specialised for the detection of light.