Introduction to Psychology grows directly from an earlier book, Psychology: A Factual Textbook, by the same editors, which appeared in 1935. The central aim of the earlier book was the production of a 'factual' textbook unembarrassed by 'theories'. In order to achieve this end, nineteen men wrote nineteen chapters in their special fields. These chapters were unified by Boring, Langfeld, and Weld as editors of the book.

The present volume started out as a revision of the earlier Textbook. However, in the process the revision became so heroic that it became essentially a new book although the aim and the method of execution of the old one were retained. Boring, Langfeld, and Weld have again acted as organizing, unifying and rewriting editors. Five new men have joined the original group, while the work of six of the earlier contributors has been rewritten. This brings the collaborating staff of the Introduction to twenty-four men.

Like its predecessor, this book tries to avoid 'theories' and