Using data from observation of twenty-seven out of forty children (aged two to five) in a psychoanalytic study group's nursery school and interviews with their mothers, the authors point out that there are really two separate types of transitional objects—attachments forming either before age one or after age two. They define the early type in detail. In addition, they describe the characteristics of the object and the child's relationship to it. Children become attached to 'primary transitional objects' in the first year of life, usually by six months, and the attachment lasts at least a year. (In the population studied,