Co-evolution between sociality and dispersal: The role of synergistic cooperative benefits

► Altruism can invade if dispersal and cooperation are negatively correlated. ► Dispersal levels are less important after cooperation increases in frequency. ► Synergistic benefits of cooperation expand the conditions where sociality evolves. ► Demographic parameters remain influential when altruism is less costly. ► This work generalizes previous model results to a wider range of social organisms.