Helmut Kentler (2 July 1928 – 9 July 2008) was a German psychologist, sexologist and professor of social education at the University of Hannover. From the late 1960s until the early 1990s, with the authorization and financial support of the Berlin Senate, Kentler placed several neglected youth as foster children in the homes of single pedophile fathers. Kentler believed pedophiles could make acceptable foster parents, and that any sexual contact would be relatively harmless if it were not forced. This project was later dubbed the "Kentler Experiment" or the "Kentler Project." Kentler later changed his mind on pedophiles having sexual contact with children, and described pedophilia as a "sexual disorder".

Early life and education Kentler was born to a German family. His father worked in the Nazi German government. Kentler's parents followed the childcare techniques of Moritz Schreber, who argued the authority of fathers and suppression of children's emotion would create a stronger race of men.

After graduating from high school, Kentler wanted to study theology to become a pastor. His father insisted he undertake technical vocational training. Kentler completed an apprenticeship as a locksmith at the Lokomotivfabrik Henschel in Kassel and subsequently studied electrical engineering at the RWTH Aachen. After the death of his father, he withdrew from his studies in Aachen. From 1953 to 1954, he trained as an interpreter in English and French.From: Parents learn sexual education, inside cover Afterwards, he studied psychology, medicine, education and philosophy in Switzerland and Freiburg, Germany. During his studies, he participated in a field trial with young workers, which he documented and reflected on later in his 1959 book, Youth Work in the Industrial World. In it, he still explicitly proclaimed his Christian faith (according to Rüdiger Lautmann in his 2008 obituary on Kentler for the Humanistische Union); in later publications, this was no longer the case. In 1960 he passed the main diploma examination for psychology.

Career After completing his studies he initially worked as a youth education officer at the . Afterwards, he worked from 1962 to 1965 as a research assistant and "first pedagogue" in the (protestant youth work) at . The theory of emancipatory youth work, which he played a decisive role in developing, made him known nationwide. retrieved on 12 March 2012 The following year he was assistant to Klaus Mollenhauer at the . Afterwards, he became head of the Department for Social Pedagogy and Adult Education at the Berlin and from 1967 to 1974 departmental director there. In 1975, he received his doctorate in Hanover with the dissertation Parents learn sexual education, which also appeared as a book and reached a total circulation of 30,000 copies by the 1990s. In 1976, he was appointed as a university lecturer for the training of vocational school teachers for special education at the University of Hanover, where he taught until his retirement in 1996.

Kentler was one of the advocates of "emancipatory" youth work and is considered a representative of sexual education of the 1960s and 1970s. In his work as a court expert and expert on child and adolescent sexuality, he achieved recognition in professional circles. From 1979 to 1982 he was president of the German Society for Social-Scientific Sexuality Research; later he was on the advisory board of the Humanist Union. He was also a member of the .

For Helmut Kentler, theory and practice were tightly knit throughout his life. His development of a theory of emancipatory youth work grew out of his work with adolescents and young adults during his studies and the five years he spent working in church educational institutions. He implemented group pedagogy and teamwork in theory and practice as a trusting and respectful cooperation of pedagogues with different professional competencies, and attempted to gain insight into psychosocial connections for learning and emancipation processes for young people and adults.See: Youth work in the industrial world – Consequences for youth work This was a new concept for church educational work in the 1960s. In addition to his professional duties, he worked in various fields of pedagogical practice in an advisory and teaching capacity. From 1970 to 1974, he sat on the pedagogical advisory board of the first residential community for orphaned children at Maxdorfer Steig, sponsored by the Berlin Senate.see: Neuer Rundbrief. Information on family, youth and sport, Berlin, 3/1970, 2/1972, 2/1974

During the student riots in Berlin, Kentler was temporarily active as a "psychological consultant for police issues".Berlin / Polizei: Feind im Innern, Der Spiegel, 7. August 1967 The sexual liberation movement of Berlin students in communes and shared flats resulted in his advocacy for emancipatory sexual education in the home.Parents learn sexual education, Rowohlt, 1975 This was reflected scientifically in his dissertation in 1975, rendering him an expert in sexual education for the course of his professional life.

Kentler experiment In a model experiment in Berlin that began at the end of the 1960s, Kentler placed several neglected 13 to 15-year-old boys he considered "secondary mental defectives" with pedophiles he knew, claiming this would reintegrate them into society and allow them to grow into mature adults.Nina Apin, Astrid Geisler: Der Versuch. In: taz of 14 September 2013, retrieved on 26 July 2017. This occurred with knowledge and approval of Berlin's Senate Youth Administration. Due to the criminal offense associated with it, he wrote about the experiment publicly first in 1980, when the statute of limitations had expired. Kentler claimed that the experiment would help the children to regain social stability through exposure to pedophiles. He was aware that the adults would most likely perform sexual acts on the minors.

At a factional hearing of the FDP in 1981, Kentler reported: "These people only endured these moronic boys because they were in love and infatuated with them."Liberalism: FDP was more tolerant towards pedophiles than previously known, Spiegel Online, 1. September 2013. In an expert opinion in 1988 for the Senatsverwaltung für Familie, Frauen und Jugend he described the results of the trial as "a complete success". He maintained contact with the abuse victims during his teaching activities in Hanover, and in an expert opinion for the Berlin Family Court in the early 1990s recommended that one of the abused youths remain with his pedophile foster father, whom he described as a pedagogical natural talent.Jutta Rinas: Sexual abuse: The professor and the little boys, in: Hannoversche Allgemeine Zeitung, 12 January 2018, p. 18

From Hanover, Kentler still supervised a pedophile foster father of several boys in Berlin as late as 1988-1999, frequently meeting with the man and a boy and writing to Berlin youth authorities and judges.

By 1999 Kentler had apparently changed his mind on pedophiles having sexual contact with children, describing pedophilia in an interview as a "sexual disorder" and stating that in such a relation, the adult will always have the "monopoly on definition."

Kentler was homosexual, single and had three adoptive sons and several foster children. One former associate of Kentler later stated that two of the foster children had come to her for therapy as Kentler had sexually abused them.

Positions Sexuality and society In Kentler's view, it was not enough for parents to avoid putting obstacles in the way of their children's sexual desires. Rather, parents should introduce their children to sexuality, because otherwise they "risk leaving them sexually underdeveloped, to become sexual cripples".Parents learn sexual education, S. 32 Parents would bear a high degree of responsibility here: "Parents must be made aware that a good relationship of trust between children and parents cannot be maintained if children are denied the satisfaction of needs as urgent as sexual ones."H. Kentler: "Sex education. 1970, p. 179 Early experiences of coitus are useful because teenagers with such experience "demand an independent world of teenagers and more often reject the norms of adults".Kentler: Sexual Education, p. 171

One of Kentler's particular concerns was the reduction of sexual repression amongst girls: "Often the repressive education was so successful that they no longer feel any sexual pressure. A sexually open-minded boy then calls such a girl 'uptight', and 'unfashionable'."Kentler: Sex Education, p. 173

Based on his view that children can have sexual needs even before puberty, he made a distinction between voluntary sexual interactions among peers and with adults from sexual abuse of children: "Sexually satisfied children who have a good relationship of trust with their parents, especially in sexual matters, are best protected against sexual seduction and sexual attacks."Parents learn sex education, p. 103 Kentler warned the parents against being concerned over rape or molestation of children by adults: "The wrong thing to do now would be for parents to lose their nerve, panic and run straight to the police. If the adult was considerate and tender, the child could even have enjoyed sexual contact with him".Parents learn sexual education, pp. 103 f. Kentler considered equal and non-discriminatory sexual relationships between adults and children to be acceptable: "If such relationships are not discriminated against by the environment, then the more the older one feels responsible for the younger one, the more positive consequences for personality development can be expected", he wrote in 1974 in his foreword to the book Zeig mal!Zeig mal! Wuppertal 1974, foreword

Activity as court expert Kentler also acted as a forensic expert in abuse cases. In 1997, he declared about the almost 30 cases he had dealt with up to that point: "I am very proud that so far all cases I have dealt with have been terminated with the discontinuation of proceedings or even acquittals." Kentler did not attribute injustice to the sexual activity of adults with children but to the violence that may have occurred. This, however, he believed to be atypical, since "real paedophiles do not use violence but are highly sensitive to damage to children".Does the psycho wave roll over the law? In: Emma, Nov/Dec. 1997, p.  30–38 In 1999, Kentler announced the publication of a book about "the approximately 35 lawsuits against innocent people whom I have accompanied as an expert witness," but then abandoned the manuscript (Parents Under Suspicion – Of Sexual Abuse) unpublished.Rüdiger Lautmann: Obituary for Helmut Kentler, on the website of the Humanist Union; quoted after Späth/Aden: Die missbrauchte Republik, p. 145, 148. In the same year he declared:

Reception After the magazine EMMA reported on his activities in 1993, he was shouted down by feminist activists at an event in Hanover and punched in the face by an audience member.