Why is there a specific APA Style®?
APA Style® was established to codify the many components of scientific writing to facilitate clear communication and has enabled psychologists and scholars in other social and behavioral sciences to enhance the dissemination of knowledge in their respective fields.
APA Style focuses on the needs and guidelines established in psychology and other social and behavioral sciences and does not cover general rules explained in widely available style books and examples of usage with little relevance to the behavioral and social sciences.
Among the most helpful general guides to editorial style are Words into Type (Skillin & Gay, 1974) and the Chicago Manual of Style (University of Chicago Press, 2005).
Style manuals agree more often than they disagree. Where they disagree, the Publication Manual, because it is based on the special requirements of psychology, takes precedence for APA publications.