A strangely unconvincing study of men who depend on non-standard sexual behavior (featuring rubber, leather, power-playacting, etc.), which concludes that each sexual predilection is, in large part, ""the logical though unfortunate reaction of a generally shy, introverted and emotionally over-sensitive child to a restrictive sexual upbringing."" Logical reaction? Maybe so, but nearly every aspect of this study requires some defense or clarification, and at times the psychologist authors sound conversant with their data but say very little. For example, although the (mostly English) subjects were contacted through special-interest sources, the controls (""normals"") were inexplicably hard to find: ""the departure lounges of airports [proved] to be a particularly fruitful source of people who could be persuaded to help."" Relying on two questionnaires, the investigators came up with a considerable amount of data (more men prefer being hurt by a partner to hurting a partner) but they don't really come to terms with its validity. What, for instance, does ""good"" mean to the many sadomasochists (93%) who answered ""yes"" to the question ""Is (or was) your mother a good woman?"" The authors acknowledge such difficulties, consider this one ""an open matter for speculation."" In the same way, although they include a few case histories, they dismiss the lessons of psychoanalysis as unworthy. This allows them to ignore a large relevant literature and still use the occasional psychoanalytic insight. Finally, they offer conclusions--on transsexual surgery, for example--without reviewing the most recent evidence. Overall, profiles do emerge of each kind of enthusiast, and of the substantial overlap of their partialities. Yet one never discovers why these people were so ""easily conditioned,"" why all people in similar situations don't grow up developing the same intense, enduring sexual needs as this self-conscious minority. Much of the research methodology and reporting seems to have been designed to anticipate the prejudices of outsiders, to assure access, and to avoid moral judgments. But the book leaves too many questions unanswered to be useful: one reads with the conviction that truly discriminating measures are missing.