Single point motion kinematics convey emotional signals in children and adults

This study investigated whether humans recognize different emotions conveyed only by the kinematics of a single moving geometrical shape and how this competence unfolds during development, from childhood to adulthood. To this aim, animations in which a shape moved according to a happy, fearful, or neutral kinematics were shown, in a forced-choice paradigm, to 7- and 10-year-old children and adults. Accuracy and response times were recorded, and the movement of the mouse while the participants selected a response was tracked. Results showed that both 10-year-old children and adults recognize happiness and fear when conveyed solely by different kinematic with an advantage for fearful stimuli. Fearful stimuli were accurately recognized also at 7-year-olds, together with neutral stimuli, while, at this age, the accuracy for happiness was not significantly different than chance. Overall, results demonstrate that emotions can be identified by kinematics alone during both childhood and adulthood. Moreover, kinematics contributes in various measures to the comprehension of emotions, with fear kinematic recognized earlier in development and more readily even later on, when all emotions are accurately labeled.