Following evolutionary ideas, it is argued that human societies grew in size while competing with other
societies over preferred habitats. Larger human societies are more successful in competition, but they also experience
more pressures to fission. Morality unites a society by limiting infringements upon the rights of other society members.
This leads to the prediction that a belief in ‘moralizing Gods’ is more often found in larger societies. A previous analysis
of data from the Standard Cross Cultural Sample and the Ethnographic Atlas support these predictions. However, in this
paper the statistics of the tests are largely ignored. The primary aim of this paper is to illustrate that evolutionary logic
helps understanding of human social behavior.