I already referred to Oxford dictionary but I found no meaning to give sense to "identity" (bold in text) in the following text (from a psychological book)
If practitioners are dealing with someone from a family that has been traumatised, they need to know the relevant details of the critical events that have affected their client. Identity to a group that has been traumatised affects both the personal identity of the person and their continuity. Trainees can learn how to gather such information sensitively. Working with shame and self-esteem are also relevant factors for this training.
Any suggestions on what 'identity' means here?