We define two levels of uncertainties for each agent. First is the uncertainty associated with in-group members’ opinion (Uin), and second is the uncertainty associated with out-group agents’ opinion (Uout) where Uin ≥ Uout. In each interaction encounters, the agents follow the same steps as 2D BC model except that if they are from the same group, they use their in-group uncertainty (Uin) to update their opinion (i.e. attraction, rejection, or ignorance). Similarly, if two agents are from different groups, they use their out-group uncertainty (Uout) for opinion updating purpose.