“…In the decades since its original development ( Barrish et al, 1969 ), 14 randomized controlled trials (RCTs) of the GBG have been conducted of the program being implemented universally during a normal school day. Six of these were conducted in the United States ( Dolan et al, 1993 ; Hansen et al, 2010 ; Ialongo et al, 2019 , Ialongo et al, 1999 ; Reid et al, 1999 ; Tolan et al, 2020 ); two each in the Netherlands ( van Lier et al, 2004 ; Witvliet et al, 2009 ) and Canada ( Dion et al, 2011 ; Jiang et al, 2018 ); and one each in Belgium ( Leflot et al, 2010 ), Northern Ireland ( O'Keeffe, 2019 ), Estonia ( Streimann et al, 2020 ), and England (for a review, see Humphrey et al, 2021 ). The current paper reports on the findings from the RCT conducted in England.…”