Much of the incidence of incest involves practices between consenting adults. Criminal definitions of this practice vary widely from country to country. In some areas, incest is not mentioned in criminal codes, while in others broad definitions and severe punishments are prescribed. Estimates of the incidence of incest in the United States have ranged up to 17 percent of the child population, with 21 percent of all American children having been approached for incestuous purposes. Generally, studies have indicated that incest is a lower class phenomenon; however, some studies have indicated that a cross-section of the community is involved. Incest offenders are primarily adults. Contrary to common belief, most are of average intelligence. About 75 percent of all prosecuted cases involve father-daughter relationships. Although most victims develop normal lifestyles, temporary self-abusive behavior often results. Sentencing in incest cases seems to be becoming less severe in England. The article suggests that incestuous relationships between adults should be decriminalized, and that treatment in cases involving children should focus on counseling for victims and offenders and on facilitating the reconstitution of the family. A total of 58 footnotes are included.