Both sociolinguistics and psycholinguistics are relatively recent areas of study and they tend to overlap. One way in which they overlap is in the selection of topics, among them bilingualism and linguistic relativity. Studies of linguistic relativity demonstrate that, although there are clear surface distinctions between the way languages map physical reality, and although these distinctions may influence the ease of memory and description, there is no evidence that these differences are fundamental or that they prevent the formation of concepts. Concerning the question of how bilingualism affects language development, no final statements can be made. One extreme position, the balance theory, holds that each individual has only a certain amount of language learning ability and if it is divided between two languages, the knowledge of each language will be weaker. At present language testing instruments are not precise enough to test this hypothesis. While the evidence now collected seems to favor the balance theory, a great deal more study is needed on this complex question. Therefore, although no one suffers cognitively by learning one language rather than another, there will possibly be some loss in linguistic ability when two languages are learned. Unless this is offset by increased motivation, there will be a loss in other subjects. Bilingual education is closely tied to a society that accepts both languages. (JD)