Nonacs 9808788 Wasp nests in the genus Polistes are often initiated by several cooperating females. Such nests grow to considerably larger sizes than nests initiated by a single wasp. However, most of the offspring are the progeny of one dominant female, which leads to a question of why do the other females accept their subordinate status rather than nest on their own. One explanation is the theory of 'social contracts', where dominants cede to subordinates a fraction of the reproduction as incentive to stay and help. That is they allow the subordinates to rear some of their own young. This fraction can be either in sons or daughters, which makes the social contract dependent also on the sex ratio produced by the entire nest. However, sex ratios are potentially affected by environment as well as social interactions taking place on the nest. Experimental manipulation of wasp nests in the field and genetic analysis of foundresses and offspring in the laboratory will directly measure the lifetime reproductive success of subordinate wasps and test several theoretical models of sex allocation. Wasps exhibit complicated social interactions and have extensive parental care for their young not unlike birds and mammals. Therefore the theoretical insights resulting from this research are relevant for many social species. Furthermore, the wasps' greater abundance and ease of observation makes them an ideal model system for testing general questions about social evolution and parental behavior. A better understanding of the colony initiation process will also have practical considerations in pest control.