The ability to read the intentions of other people is fundamental to human thought. We automatically interpret a person's behavior not in terms of the physical motions involved, but instead in terms of the goals or intentions that give rise to these motions. Observing a child chase a soccer ball across a field, we perceive the motions of the child, but not the ball, as the expression of underlying, unobservable mental states. Research at the University of Chicago shows that this basic human capacity begins to emerge early in the first year of life.
The findings counter two other theories of early development:
that the ability to appreciate intentions is innate and another that understanding intentions does not develop until the second year of life or later. "Our findings suggest a third alternative: Early in life, infants understand certain actions as goal-directed, and this early, specific knowledge provides one basis for later developments in intentional understanding," said Amanda Woodward, Associate Professor in Psychology and the Committee on Human Development.
Her research will be reported in a paper "Infants' Understanding of Goal-Directed Action" at 9 a.m. Feb. 13 at the conference of the American Association for the Advancement of Science.
Woodward's work shows that babies understand some actions not as purely physical motions through space, but rather as being goal-directed. Initially, infants' ability to understand actions as goal-directed appears to be specific to very familiar concrete actions, like grasping. Later in the first year infants begin to understand two other important aspects of intentional action. For one, they become aware of the invisible connection between a person and the object at which she looks; that is, they have the foundation for understanding that others can attend to objects in the world even when they do not physically act on them. In addition, babies begin to understand that separate actions can be organized by an overarching plan. For example, babies might infer that when a person grasps the lid of a box, his goal is not the box itself, but rather the object inside the box.
These developments may provide the foundation for children's ability to learn from their caregivers. During the second year of life, children acquire critical abilities, including language and culturally appropriate behaviors, by observing the actions of adults.
Woodward commented, "There are most certainly aspects of intentions that infants do not yet understand. Nevertheless, in the first year of life infants have begun to tune into important components of intentional action."
Woodward and her students investigate infants' understanding of actions by using a visual habituation technique. The technique involves showing babies the same goal-directed action repeatedly. Over repeated exposures, babies become bored with the action, looking at it for less long each time it is presented. At this point, the researchers introduce a change into the action. If infants detect the change, their looking will increase as they take in this new information. When the goal of the action is changed but the person's physical motions are the same, infants respond by looking a long time at the event. When the physical motions produced by the person change but the goal is preserved, infants do not show an increase in looking. These responses indicate that infants pay special attention to the goal of the action. Woodward's results show that babies' awareness of others' goals may grow from their own experiences producing goal-directed actions.
During the first year of life, there are dramatic changes in infants' ability to organize their own goal-directed actions. Woodward and her students have found that these developments are correlated with infants' responses to the actions of other people. Moreover, recent evidence shows that learning a new action impacts infants' understanding of others' actions. Woodward and her colleagues taught 3-month-old infants a new goal-directed action--using Velcro mittens to pick up a toy. Infants then observed an adult using a mitten to grasp objects. Infants who had used the mittens interpreted this observed action as goal-directed, but infants who had not used the mittens did not. Woodward is among a group of researchers with the Center for Early Childhood Research at the University, an innovative program to study early childhood development and policy.