Back in 2006, a study that went on to gain prominence found that 18-month-olds were willing to be helpful even without being prompted. Many assumed this was evidence of innate altruism, but new research out of Stanford and published in the Proceedings of the National Academy of Sciences suggests that these kids were actually primed by the playful researchers, if subtly, to display generosity—which means that altruistic behavior may be dictated by our experiences, however brief, instead of mere instinct, reports Stanford News. "People often call something 'innate' because they don't understand the kinds of subtle experiences that can make something, like altruism, flourish," says the lead author, admitting that "the findings will stir up some controversy, but in a good way."
To investigate the effect of the original study's priming, researchers mimicked it with a group of 34 toddlers, rolling a ball back and forth with the child while chatting, then knocking over an object to see if the child would pick it up. They split the group in two; in the second group, the adult and child played with their own ball independently while talking. Turns out the kids who played with the adult were three times as likely to help out and pick up the dropped object. "Kids are always on the lookout for social cues, and this is a very prominent one," says another researcher. "Does the person's play indicate that they'll care for me? These actions communicate a mutuality, and the child responds in kind." To foster altruism at home, the researchers suggest, model it, reports Yahoo. (Altruism has been linked to a specific gene.)