This article introduces the reader to a new model of group psychotherapy within the attachment field that extends the paradigm for developmental psychology opened by the Bowlby-Ainsworth attachment theory. It is based on the theoretical work of Heard and Lake (1986, 1997) and the research carried out by McCluskey (1999, 2005). The theory posits a new understanding of what we mean by the ‘self’. The theory, which is called ‘Attachment-based interest-sharing’ (TABIS), suggests that there is a dynamic process that comes into being whenever there is a threat to the self, made up of seven pre-programmed systems functioning as an integrated whole.