In a nutshell, psychogenealogy is a therapeutic frame which seeks to identify and treat the negative effects of transgenerational transmission within an individual person's life.
This approach is based on the observation that transmission within family groups occurs across generations in different and sometimes curious ways. Some of these are quite obvious, and in some cases highly formalised, as in the drawing up of wills and testaments. In other cases, the modes of transmission are quite subtle and even invisible, such as naming a child after a secret lover or a deceased relative. Yes, people do these kinds of things. In certain family groups, the modes of transmission are quite specific and culturally bound. Some families even draw up secret agreements like the Mulliez familly in France to maintain a balance between economic success and the social welfare of its members. What all family groups share is an inherent tendency to transmit those elements necessary for the continued survival of the group.
This underlines one of the premises of the psychogenealogy frame: the group is more important than the individual. Gloups! The ego takes a blow here. A group mobilises its individual members to satisfy group needs first before satisfying individual ones. This is most powerful when the individual is not even aware they are fulfilling a group function. Taking over the family business from his father, a son might believe this is the most natural thing to do, as everyone else in the family does. He gets groomed for the part. And this son may well be fulfilling a group need to ensure economic and social survival way beyond his own individual need to the point where his health suffers or his marriage falls apart and when he starts to ask, what's going on here.
Another premise in this approach is that when a child is born, the child has no personal memory of itself. That is what a child develops over time as it grows into an adult. And just like being doted in the DNA with an immunity system inherited from parents, grand parents and all those who came before, a child is also doted with an emotional and psychological DNA chain from its parents and family which enables the child to function successfully in that particular family context. These layers of memory which have been transmitted to the child become the invisible foundations on which the child then goes on to construct its own individual memory of itself.
When all goes well, no one asks any questions. But psychogenealogy attempts to find workable answers when elements embedded in the family memory are now limiting an individual in a particular way.