You can't always get what you want: infants understand failed goal-directed actions.

At what age do infants understand that goals exist independently of the actions that result from them? Exploring infants' understanding of failed intentional actions-when the goal of the action is unfulfilled and thus not apparent in the actor's movements-is a critical step in answering this question. Using a visual habituation paradigm, we assessed when infants understand that a failed intentional action is goal directed and whether an understanding of successful intentional actions (actions that do overtly attain their goals) precedes an understanding of failed intentional actions. Results demonstrated that 10- and 12-month-olds recognized the goal directedness of both successful and failed reaching actions. Eight-month-olds also recognized the goal directedness of successful actions, but not of unsuccessful attempts. Thus, by the end of the 1st year of life, infants possess an impressive understanding of intentional action, and an understanding of failed intentional actions follows an earlier understanding of successful ones.