Maybe the animals would aid people under any circumstances, assuming a reward would come their way down the line. The final step was to see if chimps would assist each other. So Warneken rigged apparatuses where one caged chimp could help a neighbor reach an inaccessible banana or piece of watermelon. There was no hope of getting a bite for themselves, yet the empowered chimps fed their fellow apes regardless.
Warneken’s chimp work makes the case that human altruism is a trait that evolution has apparently endowed us with at birth. But under what circumstances are toddlers altruistic? Some recent chimp studies suggest that chimps won’t help others unless they witness the dismay of the creature in need. Are human children likewise “reactive” helpers, or can they come to another’s assistance without social cues? Warneken created a scenario in which a clueless experimenter fools around with a bunch of milk cans at a table as a 2-year-old looks on. Unbeknown to the adult, some cans start to roll off the edge.
The experimenter doesn’t ask the toddler for help: She doesn’t even realize that a problem exists. Yet many of the children tested read the situation correctly and rushed to her aid, often yelling “Your can fell!” with great alacrity before handing it back. “You can see the birth of this proactive helping behavior from around 1.5 to 2.5 years of age,” Warneken explains. “The children don’t need solicitation for helping. They do it voluntarily.” Proactive helping may be a uniquely human skill.
Criticisms of the “nice baby” research are varied, and the work with the youngest kids is perhaps the most controversial. Over the summer, a group of New Zealand scientists challenged Kiley Hamlin’s watershed “helper/hinderer” study, making international headlines of their own.
They charged that Hamlin and her co-workers had misidentified the key stimuli: Rather than making nuanced moral judgments about kindly triangles and antisocial squares (or vice versa, since the researchers had also switched the roles assigned to each shape), Hamlin’s subjects were merely reacting to simple physical events in the experimental setup. The babies liked the bouncing motion of the triumphant circle at the top of the hill after the triangle helped it reach the summit, and they didn’t like the way the circle occasionally collided with the other shapes.
Hamlin and her colleagues responded that the New Zealanders’ re-creation of their experiment was flawed (for one thing, they let the circle’s goggle eyes look down instead of pointing at the summit, confusing the babies’ sense of the goal). Plus, the Yale team had replicated its results through the puppet shows, evidence that the critics didn’t address.
Though Hamlin persuasively dismissed their objections, such methodological worries are never far from baby researchers’ minds. For instance, Tasimi had a sneaking suspicion that in some versions of his puppet shows, the babies were choosing orange puppets over green ones not because they had sided with good over evil but simply because they liked the color orange. (Still, the babies’ preference for helpful bunnies persisted even when the researchers switched the shirt colors.)
Other critics, meanwhile, fault the developmental philosophy behind the experiments. Babies may look like they’re endowed with robust social skills, these researchers argue, but actually they start from scratch with only senses and reflexes, and, largely through interaction with their mothers, learn about the social world in an astonishingly short period of time. “I don’t think they are born with knowledge,” says Jeremy Carpendale, a psychologist at Simon Fraser University. A toddler’s moral perspective, he says, is not a given.
And still other scientists think the baby studies underestimate the power of regional culture. Joe Henrich, a University of British Columbia psychologist, says qualities like altruism and moral logic cannot be exclusively genetic, as evinced by the wide variety of helping behaviors in hunter-gatherer and small-scale horticulturist groups across the world, especially compared with Western norms. Ideas of the public good and appropriate punishment, for instance, are not fixed across societies: Among the Matsigenka people of the Peruvian Amazon, where Henrich works, helping rarely occurs outside of the immediate household, if only because members of the tribe tend to live with relatives.