By the age of 14 months, infants are masters of imitation. They mimic all sorts of behaviors, including laboratory antics such as touching one's forehead to a box that then lights up.
Babies on the brink of toddlerhood are not indiscriminate copycats, however. They sometimes opt for simpler ways to do what an adult shows them, signaling a budding capacity for evaluating the sensibility of others' behavior, according to a study in the Feb. 14 Nature.
György Gergely of the Hungarian Academy of Sciences in Budapest and his colleagues studied 14 infants, all 14 months old, who watched a female experimenter perform the forehead-to-light-box trick under two conditions. In an initial series of trials, the woman pretended to be cold and executed the head action while her hands held a blanket around her. In a second set of trials, she performed the same head maneuver with no blanket, her hands resting next to the light box.