Posted by Dave: Parallel playing is akin to writing poetry, fragments, often disparate, are blended into a collage-like whole. In a real life therapy session parallel play leads to a rough draft for a 
poem, not a finished product. The sense of the whole gives new meanings to the parts. In the case of therapy with adults; words and ideas are the toys, assigned the meaning needed to continue playing. Structured intentional play is a barrier to the rich ambiguity of parallel play. Parallel playing involves play not only with words but with syntax or grammar.
There is a form of parallel play which can take place in conversation. I call it Associative Communication. There is no “no” in it. You tell me a thought, I don’t judge it, but say what it leads me to think about.
I am providing a picture of parallel play that can be adapted to thinking about what is possible in a family therapy interview. What I am illustrating here, by inference, is the possibility of playing alongside someone without intruding in a way that stimulates restriction, defiance or withdrawal. There is no specific direction. The personhood of the therapist and the personhood of the family members are both part of the dynamics of therapy. This playing opens up the possibility for the entry of the Self of the therapist and of any family member, that is, for whole person entry into the therapeutic process.
As a therapist, I can feel stuck in almost any clinical setting. One of the clearer situations is when I am doing therapeutic work with a family where there is an ambiguous medical disorder. When I feel stuck, no one knows it nor are they likely to observe the corrective process even though it occurs right in front of them. I move inside myself, to an imaginary place in the center of myself, just below the sternum. I position my consciousness there, and take whatever floats in from my whole body mind mechanism as a comment or observation. It is something like autohypnosis.
In parallel play, the therapist’s default position is as a separate self rather than as a mirror or companion. The separate self has its own experience, and there is no intentional effort or obligation to be congruent with the Other. In fact it is important to be slightly noncongruent. The engaged non-congruence produces therapeutic energy and the foundation for a peer relationship with intimacy.
The playing that occurs is not a playing ‘with’. The model is Parallel Play. The play occurs in shared space, but the Self remains separate—in a closely approximated Parallel Universe. Parallel play is the ground for developing intimate peer relationships. Parallel play is the ground for non-manipulative caring.