An American psychology professor tracks down evidence suggesting that Wolfgang Kohler, a major contributor to the development of Gestalt psychology, led a double life as a German spy during WW I. Ley (Psychology & Statistics/SUNY at Albany) was on his way to a sabbatical in England when he stopped by Tenerife in the Canary Islands to pay homage at the site of Kohler's ground-breaking experiments on the cognitive abilities of apes. There he encountered Kohler's former assistant, a wizened local craftsman who confided to Ley that the experiments were a cover for then-German citizen (later American) Kohler's real mission: the operation of a short-wave radio to clear German U-boats for fueling off Africa's western coast. Intrigued, Ley dropped all other interests to investigate the formidable psychologist's past, perusing WW I military records in England and Germany, interviewing elderly residents of Tenerife, and talking with Kohler's family and former associates. The result is a portrait of a secretive, coldhearted intellectual who deserted his children in the name of science and freedom and who, the evidence virtually concludes, spied for his country while studying cognition in primates on the Spanish island. Ley fails to mention that it was commonplace in the first half of this century for patriotic scientists to gather intelligence for their governments while abroad--a practice discouraged only fairly recently in an effort to maintain scientists' credibility in foreign countries. In any case, too dry and plodding to appeal to any but the most determined Kohler enthusiasts.