Despite common use of the term ‘sibling-rivalry’ for Hindu-Muslim conflict in British India, there are few or no attempts to explain this phenomenon from a proper theoretical foci. By employing an indigenous interpersonal conflict model, this article seeks to examine Hindu-Muslim conflict in the pre-partition period. This draws on the dynamics of intimate rivalry among family members to explain Hindu-Muslim conflict dynamics from a fresh psycho-cultural perspective. The institution of joint-family is the most pervasive and the most influential institution in the subcontinent shaping certain views regarding the functioning of other institutions in society; including in the political sphere. People use the concrete knowledge learned inside their families to reason about more abstract phenomena such as group conflict. Therefore, the conflict dynamics associated with the family institution are extrapolated onto intergroup conflicts.