For any resident adhesiveness value between and , we display, in black: the minimal benefit-to-cost ratio for a social (or positive) mutation to be selected; in red: the maximal benefit-to-cost ratio such that this mutation is altruistic. Let us choose a fixed (i.e. an horizontal line in the graph). According to the value of , the fate and the social status of positive mutations change. For low (), all social mutations are altruistic but none of them is ever selected: the population is doomed to full asociality. For intermediate (between and ), social mutations are favored as soon as overcomes a threshold (crossing of the black line with the horizontal line ), and are altruistic all along the evolutionary dynamics. For large (), once the threshold is overcome and increases, social mutations are altruistic until some value of (crossing of the red line with the horizontal line ); afterwards, social mutations turn directly beneficial.