What word learners do when input contradicts the mutual exclusivity assumption.

In 4 studies, 3- to 5-year-olds heard 2 novel English labels each applied to the same novel object by a different adult. In all 4 studies, about half of the children accepted both labels, suggesting that hearing 2 labels applied to an object offers strong enough evidence for some to override mutual exclusivity. Nonetheless, about half of the children honored mutual exclusivity and hence accepted only 1 label; they also seemed to keep both labels in mind for at least a few minutes and settled on whichever label they re-encountered first. This strategy allows children to make an informed choice between 2 apparently equally good labels, without straining their limited memory capacities.