Straight--straightaway--is heterosexual and this discussion is intended as a prophylactic primer for parents to prevent sexual inversion in their child. The book has an introduction by the Director of the National Institute of Mental Health and is based on various studies in general and the work of the doctors Bieber and Evelyn Hooker in particular. Both agreement and finite evidence is naturally hard to come by but there seem to be two very positive preventatives: a relaxed, sensible, tolerant home; and a parental love which is not engulfing. The Wydens review various misconceptions, causal factors (the dominant mother; puritanical/rigid father); homes; specific situations (divorce, death, military service--not a determinant) and cultural trends which are just as significant as the home. ""Curing,"" the final section, chiefly entails therapy (before the age of 35). . . . Mr. Wyden has done other books on other problems (overweight; delinquency in the suburbs, etc.) and this is a safe referral at the popular level.