Abstract
In this paper some recent work from our laboratory on the development of social at- tachments is reviewed and related to current thinking in the field of sexual imprinting. Major factors likely to affect attachment of a developing individual are stimulus value of, and age and duration of exposure to, companions. Some limitations of the use of these factors in current experimental research are discussed. It is argued that, in order to understand the long-term effects of early attachments, future research should direct more attention to analyse the behavioural situation at the time early attachments are developing, as well as at the time that later effects are measured.