idiosynkrasie

Idiosynkrasie, often rendered in English as idiosyncrasy, is a term used to describe a peculiarity or characteristic that is specific to an individual or a small group. It refers to a way of thinking, feeling, or behaving that stands out from general norms, though it is not necessarily harmful. Idiosynkrasie can cover private preferences, habits, or ways of interpreting information that others may not share.

The word derives from Greek idios "one's own" and synkrasia (temperament or mixture), and entered modern usage in the early modern period.

In psychology and sociology, idiosynkrasie characterizes personal patterns that contribute to identity and social diversity rather than pathology. In medicine and pharmacology, an idiosyncratic reaction is an adverse effect that occurs unpredictably in certain individuals and is not explained by dose or known pharmacology.

Examples include a distinctive habit such as always arranging objects in a specific order; a unique linguistic tic; or a theoretical preference that shapes a scientist's interpretations. In culture and technology, idiosyncrasies of a group can reflect historical influences or organizational norms.

Related terms include idiosyncrasy, peculiarity, and quirk.