Table 2 Overview of selected studies on martial arts and aggression.
Year Author Sample size Target group* Methodology Martial art Measured effect Positive or negative effect among MA
1980 Rothpearl 152 General Cross-sectional (level of experience) Karate Hostility Positive among advanced MA
1981 Nosanchuk 41 General Cross-sectional (level of experience) Karate Aggressive fantasy Positive among advanced MA
1990 Daniels & Thornton 80 General Cross-sectional (level of experience)+ (comparison different martial arts) Karate, ju jitsu, badminton, rugby, control Hostility Positive among advanced MA
1991 Skelton et al. 68 Youth Cross-sectional (level of experience) Taekwondo Aggressiveness Positive among advanced MA
1992 Daniels & Thornton 79 General Cross-sectional (level of experience) Karate, ju jitsu, badminton, rugby Hostility Positive among advanced MA
1994 Edelman 15 Youth Longitudinal (school-linked program) Aikido Hostility and aggressiveness Positive over time among MA
1999 Lamarre & Nosanchuk 51 General Cross-sectional (level of experience) Judo Aggressiveness Positive among advanced MA
2001 Björkqvist & Varhama 319 General Cross-sectional (comparison different martial arts) Karate, wrestling and boxing, non-contact sports, no sports Attitudes towards violent conflict resolution Positive among male, negative among female karateka
2001 Zivin et al. 60 Youth Longitudinal (school-linked program) Kempo Hostility and aggressiveness Positive over time among MA
2001 Reynes & Lorant 150 Youth Cross-sectional (comparison different martial arts) Judo, karate, control Aggressiveness No difference compared to control (judo more anger than control)
2002 Reynes & Lorant (a) 8 Youth Longitudinal Judo, control Aggressiveness Negative compared to control group
2002 Reynes & Lorant (b) 9 Youth Longitudinal Karate, control Aggressiveness No effect compared to control, positive effect compared to judoka
2004 Reynes & Lorant 43 Youth Longitudinal (comparison different martial arts) Judo, karate Aggressiveness No effect among karate, negative among judo
2005 Endresen & Olweus 477 Youth Longitudinal Boxing, weightlifting, wrestling, oriental martial arts, non-participants Violent and antisocial behavior Negative among MA
2007 Wargo et al. 40 General Cross-sectional (level of experience) Taekwondo,karate Aggressiveness Neither positive nor negative
2009 Steyn & Roux 72 Youth Cross-sectional (comparison different groups) Taekwondo, hockey, non-participants Verbal aggression and hostility Positive among MA
* General (general population) = adults, adolescents and/or children are pooled together into one group. Youth = youngster under the age of 18.
† MA = martial artists.