This paper attempts to address some of the difficulties and complexities which I have encountered in working with children caught in an enveloping and invasive relationship with mother such that on a number of levels they become indistinguishable one from the other. It borrows from the world of natural science the idea of diffusion, that is:

the random movement of substances from a region of high to a region of low concentration down a concentration gradient, the rate of movement is determined by how steep the gradient is and diffusion is more rapid where the relative difference in concentrations is large.

and applies it to other than physiological processes in an attempt to describe and understand the nature of the ‘psychic flow’ between three particular mother-child dyads.