Kenneth S. Isaacs

TL;DR: In psychotherapy research, one is often hard pressed to make sense out of the many behaviors, processes, and other phenomena which can be observed in the therapy situation as discussed by the authors, such as facial expressions which are so short-lived that they seem to be quicker-than-the-eye.

TL;DR: The early psychoanalytic formulations were primarily in terms of affectivity as discussed by the authors, and further exploration of the place of affect in normal and abnormal development of personality was relegated to passing references in the literature on technique.