On one hand, the children of Holocaust survivors, versus the comparison subjects, have a significantly higher current and lifetime prevalence of PTSD and other psychiatric disorders. What would explain this difference? There was no significant difference of lifetime traumatic events between the offspring and comparison groups. The findings of this study demonstrate a higher vulnerability in the adult children of Holocaust survivors. What would cause this vulnerability? What degree of the variance might be genetic versus nongenetic? What is the mechanism of the nongenetic intergenerational transmission that might produce this vulnerability? Future studies could test various hypotheses. Although in this study, "all subjects were born at least 1 year after the end of World War II," and seven offspring had only a father who was a survivor, are there intrauterine effects of maternal exposure to a traumatic event and its aftermath during gestation that sensitize the fetus? Do these parents lack the ability to sufficiently nurture their children because of the effects of the Holocaust on themselves? To explore these questions, we need to have data on the characteristics of the parents (4). Is the transmission effected through learned behavior? Are the children traumatized by hearing parental stories of the Holocaust and witnessing the chronic suffering of their parents? In this study, there was no comparison group consisting of offspring raised apart from their Holocaust survivor parents by individuals who were not Holocaust survivors.