custom, habitual group pattern of behavior that is transmitted from one generation to another and is not biologically determined. Since societies are perpetually changing, no matter how slowly, all customs are basically impermanent. If short-lived, they are more properly called fashions. Customs form the core of human culture and are stronger and more persistent in preindustrial societies than in industrial ones, in rural than in urban areas. When formalized in the social or religious sphere it leads to ethics, and when enforced in the sphere of rights and duties, custom leads to law. See folkways; mores.