English is the dominant language of the collection. Materials in Western Europe languages are also collected in varying degrees of intensity. Materials in Slavic and Eastern European languages and materials in Asian and Middle Eastern languages are collected only in cooperation with the Slavic and Eastern European Library and the Asian Library, respectively. The writings of major psychologists are acquired in the original language. The primary focus of the collection is on works concerning the U.S. and U.K., with a secondary focus on Western Europe and the U.S.S.R. Materials focusing on Japan, the Middle East, Scandinavia, South America, and Southeast Asia are acquired selectively.
Emphasis is on scholarly treatment rather than popularization, textbooks, and children's literature.
The Undergraduate Library normally collects more popular treatments and the Education and Social Sciences Library collects children's literature for its School Collection. In addition, an effort is made to collect publications directly associated with Psychology and its related subjects, with a strong emphasis on the theory and philosophy of psychology as a science as well as its application to social and personal problems. Of specific interest are biological psychology, clinical psychology, cognitive psychology, developmental psychology, engineering psychology, experimental psychology, personality, psychological measurement, and social psychology. Works on industrial, organizational, and personnel psychology, especially those applying psychological theory, methods, and research to business and industrial problems and the behavior of individuals in organizations, are within the purview of the psychology collection. Because of the close relationship of biological and physiological psychology with biology, some relevant biological psychology materials are collected by the Biology Library.