In 2007, a study by Hamlin, Wynn and Bloom was published in Nature claiming to show that preverbal babies had what could be described as a ‘moral compass’ (not the authors’ own terms in the article). From the abstract:
Here we show that 6- and 10-month-old infants take into account an individual's actions towards others in evaluating that individual as appealing or aversive: infants prefer an individual who helps another to one who hinders another, prefer a helping individual to a neutral individual, and prefer a neutral individual to a hindering individual. These findings constitute evidence that preverbal infants assess individuals on the basis of their behaviour towards others. This capacity may serve as the foundation for moral thought and action, and its early developmental emergence supports the view that social evaluation is a biological adaptation.
This was seen as a major breakthrough for the perennial nature vs. nurture debate with respect to morality: here are young infants, presumably having had little time to be indoctrinated on the ins and outs of moral behavior, showing a clear preference for helpers over hinderers. The authors themselves viewed their results as supporting the view that this is likely to be a biological adaptation.
But did the babies really have a preference for the helper qua helper? A group of researchers at the University of Otago thought they had found a glitch in the experimental set up of the original study, and thus conducted similar experiments to test their hypothesis (paper here). The hypothesis was that, rather than showing a preference for the helper for its helping behavior, what the babies in fact did was to show a preference for the ‘bouncy-ness’ of the climber in the helping condition. As you can see for yourself on the video above, when helped to make it to the top of the mountain, the red circle bounces slightly; when pushed down the mountain by the hinderer, no bouncing occurs. So the Otago researchers changed the set up so that bouncing would occur after the hinderer’s intervention instead of after the helper’s. As they predicted, infants no longer showed a preference for the helper, and instead typically went for the character which had caused the climber to bounce – the hinderer, in this case.
The authors of the original study replied, pointing out that their results have been replicated by themselves and by others without the bouncing factor. They also noted that a number of other independent studies also seem to support the claim that babies have a ‘moral compass’. So clearly, the debate isn’t over yet.
At any rate, the new experiment serves as a warning against over-interpreting experimental results, in particular of experiments with preverbal babies. What was first interpreted as a preference for helping behavior may just as well have been a preference for bouncy behavior – and that babies like bouncy things is no news to anyone, really. This debate also illustrates how difficult it is to design experiments to test such higher order concepts such as ‘moral behavior’ while ensuring that one is not dealing with something much more prosaic which happens to be part of the experimental set up.
Personally, I tend to be on the ‘nurture/culture’ side of the debate, but I also believe (from personal experience as well as from other studies) that the onset of social, affectionate behavior occurs very early on in infants. Now, there may well be an evolutionary explanation for that: babies who are not ‘good’ at engaging emotionally with caregivers are simply more likely to be neglected by those caregivers and thus not to thrive; no wonder that babies tend to be such cute, responsive little things. (Incidentally, here is a video of the still face experiment, which shows a baby having a total meltdown when its mother gives it a ‘still face’ – quite painful to watch, actually!) However, there still seems to be a big gap from observing that babies are naturally sociable to claiming that infants show a preference for helping behavior.