This is an open access article under the CC BY 4.0 license (https://creativecommons.org/licenses/by/4.0/). Journal of Men's Health 2024 vol.20(1), 7-13 ©2024 The Author(s). Published by MRE Press. www.jomh.org Submitted: 29 June, 2023 Accepted: 01 September, 2023 Published: 30 January, 2024 DOI:10.22514/jomh.2024.003 ORIGINAL RESEARCH The level of the aggression in karate athletes with different handedness and belt grades Yaser Alikhajeh 1 , Maghsoud Nabilpour 1 , Gholam Rasul Mohammad Rahimi 2 , Mozhgan Ghollasimood 3 , Fatma Hilal Yagin 4, *, Burak Yagin 4 , Mehmet Gülü 5 , Luca Paolo Ardigò 6, * 1 Department of Exercise Physiology, Faculty of Educational Sciences and Psychology, University of Mohaghegh Ardabil, 676W+5CX Ardabil, Iran 2 Department of Exercise Physiology, Faculty of Sport Sciences, Ferdowsi University of Mashhad, 8G5F+8JQ Mashhad, Iran 3 Master of Science in Exercise Physiology, Ferdowsi University of Mashhad, 8G5F+8JQ Mashhad, Iran 4 Department of Biostatistics and Medical Informatics, Faculty of Medicine, Inonu University, 44000 Malatya, Turkey 5 Department of Sports Management, Faculty of Sport Sciences, Kirikkale University, 71450 Kirikkale, Turkey 6 Department of Teacher Education, NLA Høgskolen, 0166 Oslo, Norway *Correspondence hilal.yagin@inonu.edu.tr (Fatma Hilal Yagin); luca.ardigo@nla.no (Luca Paolo Ardigò) Abstract Karate athletes with different lateral talents possess different functions in terms of skills and personality characteristics in a way that handedness can be considered an advantage. Given that there is a paucity of research in the domain of personality characteristics, handedness and belt grades, the current research aims to investigate the relationship between handedness and belt grades with aggression among karate athletes. 120 male karate athletes participated. To measure handedness, we used Annette’s handedness questionnaire and to measure aggression, we used Bredemeier’s aggression questionnaire. The questionnaires were distributed among participants one day before the tournament. A two-way analysis of variance (ANOVA) was used to measure the effects of belt grades and handedness on the level of aggression. The results of the study indicated that there was no statistically significant difference in the average level of aggression between left-handed and right-handed karate athletes. There was also no statistically significant difference in the average level of aggression between karate athletes with different belt grades. Keywords Functional laterality; Handedness; Reactive aggression; Instrumental aggression; Martial arts 1. Introduction The popularity of Karate is steadily growing due to its ability to enhance both physical prowess and personal growth. Fighting sports encompass activities characterized by high-intensity, brief-duration, and anaerobic alactic metabolic demands. The athlete’s success in these sports is contingent upon several con- ditioning and coordinative attributes, including joint mobility, balance, coordination, and stimulus-response capabilities [1]. Handedness is the unequal distribution of hands in implement- ing motor skills between the two hands [2]. Polymorphism in human handedness, like the relative rarity of left-handers com- pared to right-handers, has persisted for thousands of years [3]. Reports indicate that only about 11% of the general population is left-handed [4]. In approximately 95% of individuals, the motor regions responsible for hand control are predominantly localized inside the left hemisphere [1]. This is why people most commonly use their right hands Interestingly, handedness is related to the performance of specific tasks associated with the dominance of the right or left hemisphere of the brain [5]. Research has shown that handedness can influence motor skills and cognitive functioning, suggesting that it may also play a role in athletic performance. Within the realm of elite international athletes, there exists a notable overrepresentation of left-handed individuals in various interactive sports that involve direct competition between two or more athletes, such as tennis, fencing, and boxing. However, this overrepresenta- tion is not observed in noninteractive or individual sports such as golf or swimming [6]. The left-handers (or left-footers) appear to be more common (19.5%) in what is called fast ball sports, interactive sports, and confrontational sports such as combat sports [7]. The results of the study by Baker & Schorere (2013) showed no statistically significant relationship between laterality and winning percentage, although there was a significant difference between stances for number of fights [8]. According to Fisekcioglu (2011), there is an advantage for taekwondo athletes who use their left hand in training [9]. Cingoz et al. [1] (2018) discovered that female karate and taekwondo athletes who are dominant left-handed have a slight edge over their dominant right-handed counterparts. However, there was no difference in the dominance of hand preference and the likelihood of winning a medal for male athletes in karate and taekwondo [1]. Additionally, personality characteristics have been found to influence sports performance and aggression levels among athletes. Aggressiveness is interpersonal behavior intended to cause physical harm or mental distress and can have many negative and positive effects on performance [10]. Aggressive