The American goldfinch is gregarious during the non-breeding season, when it is often found in large flocks, usually with other finches. The social hierarchy, measured by how many aggressive encounters are won by each individual, tends towards the male being dominant in the non-breeding season. During the breeding season, this finch lives in loose colonies. While the nest is being constructed, the male will act aggressively toward other males who intrude into his territory, driving them away, and the female reacts in the same way toward other females. This aggressiveness subsides once the eggs have been laid. The social hierarchy in the breeding season generally has the female dominant over the male. Dominance may change based on the value of a resource; a study published in 1987 found that starved subordinate birds were sometimes dominant in competitions over feeder access.