“…Some researchers support the hypothesis that karate training increases aggressiveness in prison inmates ( Verdot, 2008 ; Goldstein, 2011 ; Malinauskas et al, 2014 ), whereas others see no differences in aggressive behavior when comparing prison inmates with club practitioners ( Vertonghen and Theeboom, 2010 ). However, a third group of authors suggests that sports in prison offer benefits, including the ability to lower aggressiveness ( Gras, 2005 ; Lakes et al, 2013 ; Espinoza-Venegas et al, 2015 ; Gallant et al, 2015 ; Janelle, 2015 ; Witte et al, 2015 ; Lyons and Dustin Cantrell, 2016 ; Breitschuh et al, 2018 ). Sports offer practitioners a therapeutic process and may assist them in working on self-control, rehabilitation, and in understanding the prison environment ( Gras, 2005 ; Lyons and Dustin Cantrell, 2016 ).…”