THE SEXUAL INSTINCT: SHAPE OF THE EXTERNAL STIMULUS
The external stimulus, on the other hand, is highly dependent upon environment and is shaped by social forces and various accidents of experience into something relatively specific and differing from group to group and from individual to individual. The external stimulus can be almost any type of person. If one has been reared among fair-skinned, thin-lipped, straight-haired people, such a type will constitute one's ideal of beauty. If one has been reared among a dark, thick-lipped, kinky-haired race, it will be a person possessing these characteristics that will fill one with ecstasy. Even within a single group, the ideal of beauty varies from generation to generation. Some years ago, in this country the ideal of feminine beauty was a much more substantial-looking type of woman than is admired at present. A large bust and what seems to us mammoth limbs were considered attractive, whereas today the breasts are not so large and a trim figure is preferred. And within these norms of beauty, which vary with each race, nation and period of history, are all the differences of individuals whose particular experiences have given them different shades of sexual appreciation. The similarities and differences that are found seem to depend so much on environment that one sometimes wonders whether any element in the sexual object, or external stimulus, is indubitably instinctive or inborn.
The way in which the external stimulus takes shape will be understood better after we have noted the various stages in the motor response of sex. Let us first examine this process in the male. Logically it would seem that the stages in the male sexual response should be: (1) a vague restlessness; (2) visual exploration of a sexual object; (3) a tendency to approach and grasp the object with arms and hands; (4) the impulse to attain the closest possible contacts ; (5) the sensations and movements which contact with the genital organs stimulates; and (6) the reflex, involuntary muscular reactions that complete the sexual act (orgasm).
Men's Health-Erectile Dysfunction