The scientific study of moral thought and action is flourishing, even if still in its infancy. In his recent book, Just Babies, Paul Bloom provides a valuable contribution to this movement with a focus on, well, infants (and other young children). I anxiously awaited this next installment from one of my favorite psychologists, and it met my high expectations. This should be unsurprising given the quality of his other books that popularize fascinating research on the mind, including Descartes’ Baby and How Pleasure Works.

Just Babies tries to explain some of the contours of our moral minds and where they came from. It’s no surprise that, as a fan of evolutionary psychology, Bloom’s main thesis is that our basic moral capacities are in some sense innate. In particular, humans have a “moral sense” the fundamentals of which develop naturally based largely on our biology. 

Bloom approaches this complex issue with delicacy while remaining bold and interesting. Moral development of course requires a normal environment (“nurture”), but there is much provided by our nature that is unlearned, according to Bloom, similar to our ability to acquire a native language or grow arms. Now it seems uncontroversial and fairly uninteresting to claim that we have innate dispositions to act compassionately. Prosocial behavior is one thing, a moral sense another. But Bloom goes further, arguing that to a large extent we innately possess “the capacity to make certain types of judgments–to distinguish between good and bad, kindness and cruelty” (p. 32).

Moreover, being philosophically savvy, Bloom recognizes the philosophical precedence and pedigree of such a view. Among the great British moralists of the 18th century, Bloom draws most on Adam Smith, well known of course for his work in economics (including the “invisible hand” of the market). In such ways, Bloom’s distinctively scientific approach is informed by the rich literature in moral philosophy.

So what’s the evidence for this innateness hypothesis? The book draws on research from a wide range of fields, but taking center stage is Bloom’s own exciting work at Yale University and that of his colleagues, especially Kiley Hamlin and Karen Wynn. In a series of groundbreaking studies, they provide evidence that young children, even infants, have a sense of the morally good and bad and have moral preferences, such as generally preferring those who are kind to others. 

Studying the minds of babies is difficult, but there are some subtle methods scientists use. One standard way to see what babies are understanding and expecting is to track “looking times.” In one of the central studies of Bloom and his collaborators, infants watched scenes involving geometrical shapes with eyes that moved up or down a hill. One shape helped another, the climber, up the hill while a third shape hindered the climber’s progress. The initial finding was that infants around 9-12 months look longer when the climber subsequently approaches the hinderer rather than the helper—this behavior is unexpected. And the effect seems driven by the social aspect of the scene since it disappears if the ascending shape is depicted as inanimate, lacking agency. Subsequent studies showed that, when given the choice, the babies will reach for the helper rather than the hinderer—suggesting they prefer the good guy.

This might not sound very convincing, but this is just a sampling of the studies and all are well controlled. Moreover, the children are often surprisingly young; it’s some of the first evidence that preverbal infants have a sense of morality, suggesting that it is innate. And this is only one strand of evidence.

Other recent fascinating studies track children’s distributions of goods in controlled settings. One set of researchers, for example, asked kids ages 6-8 to help decide how to divide up an uneven number of rewards to two imaginary characters who cleaned up their room. When given the option, participants tended to choose to throw the extra reward away rather than give it to one of the characters and thus generate an unfair distribution. Similarly, children as young as 16 months old prefer a character who divides goods equally among the other characters and are surprised at unequal distributions (based on looking times). Still, Bloom also discusses evidence that distributions often bend toward injustice as well, especially when involving kith and kin. The point is not that we are born predominately kind and just; rather we have a sense of such distinctions.

Another important part of moral psychology that Bloom investigates is empathy and altruism. Numerous studies show that adults are more likely to help others for whom they feel empathy and toddlers will spontaneously help strangers perceived to be in need. Unlike some other researchers, however, Bloom is hesitant to champion empathy as the key to our moral sense, since research and common experience suggest that empathy, while generally important, is biased toward those who are similar to oneself (e.g. in race and gender). Again our evolutionary history, which engendered in-group tribal sentiments, shapes our current moral attitudes. Yet our moral capacities also allow us to recognize that this is problematic, so moral cognition must involve much more than empathy.

The book covers much ground that I cannot survey here. Other enthralling topics include research on psychopaths; the role of other emotions, like disgust, in moral judgment; punishment in economic games; and of course discussion of the popular “trolley” cases that attempt to uncover patterns in adult moral thinking. A broad theme, however, is that, while emotions are important building blocks of moral thought and action, they are not enough. Bloom argues that we need “sentiments plus reason” (p. 100). The emerging picture is thus a balanced and relatively optimistic one: while we are naturally endowed with some moral capacities, they are not perfectly unbiased or uncorrupted, but thankfully rational reflection can help us correct them. You’ll have to read the final chapter to get a sense of how. 

Just Babies makes some bold claims that are difficult to substantiate in one relatively brief book. One can easily be skeptical about the strength of the evidence. But Bloom doesn’t necessarily aim to have settled the issue beyond reasonable doubt. What he has done is provide a rigorous, scientifically informed case for the existence of an unlearned set of basic capacities for thinking and acting morally (or immorally). Perhaps more importantly, though, Bloom makes his case to a broad audience in his typically engaging way. It’s an enjoyable read that should at least affect how you think about the moral development of our little ones toddling their way through childhood.

© 2014 Joshua May

Joshua May is an Assistant Professor of Philosophy at the University of Alabama at Birmingham. His research is in ethics (especially moral psychology) and the theory of knowledge. His web page is: http://www.joshdmay.com/