When American Jewish psychologists Bruno Bettelheim and Lawrence Kohlberg introduced in the late 1960s their research on kibbutz child-rearing and education, they presented kibbutz as a radical, secular, collectivist experiment. The term "radical experiment" was the key to capturing the interest of their social-science-oriented audiences. Yet, as their biographers would later attest, Bettelheim and Kohlberg each found a spiritual meaning to their kibbutz research that they never shared with their readers. Those personal Jewish meanings are the primary focus of this article.