A parent places a child in the middle when the child is asked to be a carrier of adult messages, asked to keep secrets, or asked to serve as a spy in the other household. When a parent trashes the other parent to the child, half of that child is being trashed also. Such issues take their toll on a child's self-esteem and sense  of well-being. Any movement along the continuum from conflict to cooperation, no matter how small, is a move to benefit the child.

Baris, M. A., Coates, C. A., Duvall, B. B., Garrity, C. B.,Johnson,
E. T. i LaCrosse, E. R. (2001.): Working with high-conflict families
of divorce, Jason Aronson Inc., New Jersey, London