functionalism

In psychology, a broad school of thought that originated in the U.S. in the late 19th century and emphasized the total organism in its endeavours to adjust to the environment. Reacting against the school of structuralism led by Edward Bradford Titchener, functionalists such as William James, George Herbert Mead, and John Dewey stressed the importance of empirical, rational thought over an experimental trial-and-error philosophy. The movement concerned itself primarily with the practical applications of research (see applied psychology) and was critical of early forms of behaviourism.

Learn more about functionalism with a free trial on Britannica.com.

In molecules, any of numerous combinations of atoms that undergo characteristic chemical reactions themselves and in many cases influence the reactivity of the rest of the molecule. Organic compounds are often classified according to the functional groups they contain. Common functional groups include hydroxyl (singlehorzbondOH), in alcohols and phenols; carboxyl (singlehorzbondCOOH), in carboxylic acids; carbonyl (singlehorzbondCdoublehorzbondO), in aldehydes, ketones, amides, carboxylic acids, esters, and quinones; and nitro (singlehorzbondNO₂) and amino (singlehorzbondNH₂), in certain organic nitrogen compounds.

Learn more about functional group with a free trial on Britannica.com.

Generally, functional refers to something able to fulfill its purpose or function.

• Functional form and functionalism (architecture) apply to architectural design.
• Functional (mathematics) is a term applied to certain scalar-valued functions in mathematics, computer science, and Lagrangian mechanics.
• Functional (ontology) refers to a property or relation in an ontology that can only hold a single value for a given individual.
• Functional programming is used in computer science as well.
• Functional symptom is sometimes used in medicine to describe symptoms that have no current visible organic basis, e.g. if they are a result of psychological or perceptual dysfunction. Historically, functional symptoms tend to be reclassified as organic as investigative techniques improve.
• Functional group in organic chemistry (for example, "This compound has two carbonyl functions").
• Functional classification is a term used in the United States for class of road.

See also

• Function (disambiguation)
• Functionalism
• Functional group (disambiguation)