Just Babies

Bloom opens the Preface with a sharp contrast — a real act of altruism in 2005 (Virginia Postrel donating a kidney to a stranger, Sally Satel) set against a news story he read the same morning about a man who threw acid in his ex-girlfriend's face. This contrast — humanity's capacity for both astonishing goodness and horrifying cruelty — frames the book's central question.

He then recounts the "Mary Bale" incident — a middle-aged woman in England caught on security camera dropping a stray cat into a trash bin, a video that went viral on Facebook and provoked such intense public rage that the woman required police protection. Bloom presents this as an example of how extreme our instinct to punish can become.

He surveys different ways of trying to understand morality — theology (NIH director Francis Collins treating acts of selflessness as evidence of God), literature and philosophy (the intuitions of novelists and poets, normative and metaethical approaches), and finally science, studying morality with the same methods used to study language or memory. Bloom explains that, as a developmental psychologist, his own focus is on how morality emerges in babies and young children.

Quoting Thomas Jefferson's 1787 letter — that the moral sense, like an arm or a leg, is part of a person, its strength varying from person to person but granted to everyone — and drawing on Adam Smith's "The Theory of Moral Sentiments" (a work Smith himself considered superior to "The Wealth of Nations"), Bloom promises that much of the book will show how these 18th-century ideas are confirmed by modern developmental-psychology experiments.

He lists four innate moral capacities: a moral sense (distinguishing well- from ill-intentioned acts), empathy and compassion, a rudimentary sense of fairness (a preference for equal division of resources), and a rudimentary sense of justice (wanting good acts rewarded and bad acts punished) — but stresses that this innate goodness is limited: indifference and hostility toward strangers, and a tendency toward bigotry and racism, are just as natural.

Chapter 1 opens with the now-famous experiment: a one-year-old watches a puppet show in which a "nice" puppet returns a ball while a "naughty" puppet runs off with it; when a reward is placed in front of each puppet, the baby predictably takes the naughty puppet's reward — but doesn't stop there, reaching over to hit the puppet on the head. Bloom presents this as evidence of a primitive urge to "enforce justice" that exists in babies before they can even speak.

• Bloom's prose is academically precise yet enlivened by personal confessions (admitting his own moral lapses) and everyday references (a Yoda quote, the Facebook incident)
• The book is a rare blend of hard science (puppet experiments) and philosophical tradition (Jefferson, Adam Smith)
• The author is a professor of psychology and cognitive science at Yale University; his research has appeared in journals like Nature and Science