Abstract:
Criminal violence is one of the most alarming trends that has imposed a significant cost to
society. Criminal violent behaviour is a multifaceted phenomenon predisposed to various
factors such as psychological, biological, sociological and economic. However, less
attention has been given to the physiological and biological roots that influence criminal
violence. Therefore, the present study investigates the interplay between genetic (MAOA,
DAT-1 allelic variants) and socio-environmental (childhood maltreatment), and behavioural
traits (impulsivity) in criminal violence of male convicts in Sri Lanka. Male convicts
categorized as violent (N=100), non-violent (N=90) in Welikada Prison, Borella and normal
control, (N=100) were recruited for the study. All participants were surveyed using the
translated and validated Childhood Trauma Questionnaire (CTQ) and impulsivity using
Barratt Impulsivity Scale-Version 11 (BIS-11). The relationship between the above factors
was established based on six hypotheses by employing Chi-Square Test of Independence
with Phi and Cramer’s V indices, the Independent t-test followed by the Levene’s test, the
Mann-Whitney U test with the Cohen’s r, and Logistic Regression followed by Model
fitness assessed using the Omnibus Tests of Model Coefficients and the Hosmer-Lemeshow
Test. The hypotheses testing revealed positive results for MAOA low activity variant careers
to exhibit increased violent criminal behavior (p<0.05, Chi-square test), emotional neglect
to be positively associated with violent criminal behaviour (p=0.04, Independent t-test), and
motor impulsiveness was positively associated with violent criminal behaviour (p=0.039,
Mann Whiteney U test). MAOA low activity variants, emotional neglect, and motor
impulsiveness played determining roles in criminal violent behaviour of male convicts. This
study further highlights the importance of establishment and conductance of better early
childhood interventions in Sri Lankan community, especially addressing emotional neglect
in order to prevent the development of violence behavior. Particularly, the community
should be educated about childhood physical and emotional development and minimize
traumatic experiences foreseen a violent free community along with measures taken to
reduce high impulsive behaviours in individuals such as behavioural strategies and
psychological interventions.
