The "less is more" hypothesis suggests that one reason adults and children differ in their language acquisition abilities is that they also differ in other cognitive capacities: for instance, the relatively poor memory and/or processing abilities of children may make them more likely to over-regularize inconsistent input (Singleton & Newport, 2004; Hudson Kam & Newport, 2005). We investigate this hypothesis by placing adults under a high cognitive load using a standard task. Does their tendency to over-regularize in a simultaneous language-learning task increase? Results indicate that although the cognitive load is high enough to impair overall learning, neither the presence of load nor poor working memory predicts greater overregularization. This suggests that if the "less is more" hypothesis explains over-regularization in children, the relevant cognitive capacity is not one that was impaired by our load task.