Absence and Abnormality

Iso-Kikuchi syndrome with absence of ring fingers and metacarpal bone abnormality.

Localized enlargement of the spinal canal in the absence of tumour: a congenital abnormality.

When Elsberg and Dyke (1934), having studied a series of antero-posterior radiographs of normal spines, reported the range of normal variation in the distance separating the inner borders of the vertebral pedicles, they provided information which has required no important modification since that time. They pointed out that an unusual and localized increase in the distance between the pedicles w...

Defining Normality and Abnormality

Much of the practice and research conducted by clinical psychologists focuses on abnormality, also known as mental disorders, psychiatric diagnoses, or, more broadly, psychopathology. Through their training and their professional activities, clinical psychologists become very familiar with the definitions of various forms of abnormal behavior and the ways it differs from normal behavior. But be...

Abnormality, rationality, and sanity.

A growing body of studies suggests that neurological and mental abnormalities foster conformity to norms of rationality that are widely endorsed in economics and psychology, whereas normality stands in the way of rationality thus defined. Here, we outline the main findings of these studies, discuss their implications for experimental design, and consider how 'sane' some benchmarks of rationalit...

Normality and abnormality.

‘Normal’ comes from the latin norma, a carpenter’s square, and in mediaeval times meant something at a right angle or perpendicular. A few centuries later it came to mean conforming to a standard and was used in physics to refer to the average of a set of variables. If the variable concerned, such as head size or IQ, is continuous and has a normal distribution, by convention the normal range ha...