The population of Assam comprises of various tribes with their varied customs and beliefs. The current research study investigates the patterns of aggression and its different modes among tribal and non-tribal young adults of Assam residing in Guwahati city. The sample consisted of 240 young adults (120 tribal and 120 non-tribal) ranging from 18 to 24 years of age, 60 males and 60 females for both tribal and nontribals. Attempts were made to include all the prominent tribes of Assam viz. Bodo-Kachari, Karbi, Miri, Lalung, Dimasa-Kachari and Rabha tribes. Thematic Apperception Test (TAT) and a semistructured interview schedule were the tools adopted for collecting information about their family types, parental deprivation, parental relation, drug abuse in the family, settlement pattern. Mean, Standard Deviation and t-test were the statistical measures adopted in this 2x2 factorial design study. In addition to this, discriminant analysis (n-aggression= 0.001) has been worked out to strengthen the predictive validity of the obtained data. Results from the TAT scores reveal no significant difference among the two cultures on n-aggression. Both the tribal and non-tribals were found to have high aggression and further, both tribal as well as non-tribal young adults show no difference in n-aggression when compared in modes such as emotional verbal, physical social and destructive. In addition to that the study yielded an interesting finding that, no gender difference on n-aggression was found for both the cultures.