Psychoanalytic, experimental, ethological, and cross-cultural studies of transitional phenomena are reviewed and a theoretical integration is attempted. These different approaches provide a multidimensional view of the significance of transitional phenomena, particularly blanket attachment. Seemingly different theoretical positions are not necessarily contradictory but actually are complementary, and can be integrated in the light of cross-cultural findings and by using the concept of adaptation. A reexamination of the literature led to the following conclusions:

1Although the various transitional phenomena (transitional object equivalents, primary transitional object, and secondary transitional object) all share common features, clear distinctions between them can be discerned and defined. A classification is proposed according to the age of onset, the nature of the object, and the different functions it serves. This classification is desirable to clarify the current literature and to promote more scientific investigation of the subject matter in the future.