affinités

Affinités, or affinities in English, refers to a sense of natural attraction, similarity, or potential interaction between two entities. The term encompasses psychological compatibility, shared characteristics, and the likelihood of a productive or harmonious relationship. It can be used in everyday language as well as in scientific, literary, and philosophical contexts.

The word derives from Latin affinitas, meaning proximity or kinship, and entered French and other languages with a broad sense of connectedness. In practice, affinités describe how well things or people fit together, whether through common interests, similar traits, or complementary functions. In literature, the phrase affinités électives (elective affinities) is associated with Goethe’s novel Die Wahlverwandtschaften, where marriages and loyalties are tested by forces of attraction and compatibility.

In science, affinity has specific technical meanings. In chemistry and biochemistry, binding affinity measures how strongly two molecules, such as a ligand and a receptor, interact; it influences reaction outcomes and is quantified by equilibrium constants. Affinity chromatography uses selective interactions to separate substances. In broader scientific use, affinity denotes a tendency for substances or systems to associate or react under given conditions.

Social and legal contexts also employ the term. Affinity can describe kinship or social connectedness through marriage (in-law relationships) rather than by blood, a concept recognized in many legal and cultural traditions. It is also used in sociology and anthropology to discuss perceived similarity and rapport within groups.

See also: affinity, binding affinity, affinity transformation, and related concepts in science and social science.