The middle class are no less distrustful of strangers than the rich in the 1970s, the advent of the family picnic among the middle class has become an annual and extremely important event. The picnic, usually held on the isolated bank of a river, brings all of the family together, fathers, mothers, sons, daughters, cousins, nieces and nephews. Nude bathing has become a vital rite in such an affair. Eventually, the nude bathers pair off and disappear for sex. A mother may seduce her son, a father his daughter, an aunt her nephew and so on.

The widowed women in the family are given the choice of the youngest available boys.

In the poorer segment of society, incest has become more prevalent than ever. When a man dies and leaves a wife who can still bear children, she selects the strongest son, to impregnate her.

The motive? Fear. For the past five years, Dr. Ralph Dormann, a director of the Institute of Human Faetois in Santa Barbara, California has been analyzing many hundreds of incestuous case histories from all of the socioeconomic levels. His very definite conclusion is that fear of strangers outside of the family structure is causing more couples to turn to intrafamilia sex. He compares the situation to feudal times when villagers, all related to each other, erected high walls around the village to keep out intruders who threatened their safety. Today, families are erecting psychological walls, and turning inward to keep out strangers.

Is fear a strong enough motive for modern day couples to condone incestuous sexual activity? According to The Encyclopedia of Human Behavior, "… fear is a recognized threat, characterized by a feeling of disagreeable tension and an impulse to escape danger…"