From the late 1960s until the early 1990s, with the authorization and financial support of the Berlin Senate, Kentler placed several neglected youth aged 13 to 15 as foster children in the homes of single pedophile fathers.
Kentler's parents followed the childcare techniques of Daniel Gottlob Moritz Schreber, who argued the authority of fathers and suppression of children's emotion would create a stronger race of men.
Kentler completed an apprenticeship as a locksmith at the Lokomotivfabrik Henschel in Kassel and subsequently studied electrical engineering at the RWTH Aachen.
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.
[citation needed] After completing his studies he initially worked as a youth education officer at the Evangelische Akademie Arnoldshain [de].
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.
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.
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.
In a model experiment 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.
The scandal was publicly debated in 2015 and the Senate Youth Administration commissioned the political scientist Teresa Nentwig [Wikidata] of the University of Göttingen to investigate the incident and forward her findings to the relevant authorities.
"[9] In an expert opinion for the Senatsverwaltung für Familie, Frauen und Jugend he described the results of the 1988 trial as "a complete success".
[19] 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.
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.
[10] Jan Feddersen [de] praised Kentler in an obituary in the Tageszeitung of 12 July 2008, as a "meritorious fighter for a permissive sexual morality".
Like no other, Helmut Kentler embodied the humanistic task of an enlightened sex education and was also a role model for public science.
[25] In an editorial of the Frankfurter Rundschau in March 2010,[26] Stephan Hebel [de] assessed a passage from Kentler's foreword to the 1974 book Zeig mal!
[27] Due to an article by Ursula Enders in EMMA in 1997, Kentler was prevented from receiving the Magnus Hirschfeld Prize [de] in 1997 "at the last minute".
Soboczynski explained that Die Zeit had shown a lack of sensitivity in publishing the "pedophile-friendly scientist" in the late 1960s due to the connection between anti-fascism and sexual liberation, which Kentler had claimed referring to Wilhelm Reich.
[28] Georg Diez [de] subsequently criticized this text in his column on Spiegel Online: asserting Soboczynski had neither taken Kentler seriously nor really analysed him.