The Value of Rewards
Mark Lepper, ’66, has long worked on intrinsic versus extrinsic motivation. In a 1973 study, he and colleagues had children play with materials in which they’d already shown an interest (say, marker pens and drawing paper). Two of three groups received rewards for the activity—one group unexpectedly. Then those materials, along with others, were placed in the classroom and the children were observed to see what they chose to play with. The children in the expected-award group showed significantly less interest in that activity than before the study. This research has implications for anyone trying to modify a child’s behavior through a system of rewards.

What Is Real?
When do children understand that things can appear to be one thing but actually be another? In a 1983 study, John Flavell and colleagues showed 3-, 4- and 5-year-olds four such objects, including a sponge that looked like a rock. Half the children were first asked, “What does it look like?” then shown it was a sponge; the other half experienced the reality form first. Next they were asked whether they thought it looked like a sponge or a rock and whether it really really was a sponge or a rock. Most 3-year-olds answered “sponge” to both questions. The 4- and 5-year-olds generally were able to answer that it looked like a rock but was really a sponge. Distinguishing between appearance and reality—knowing that something may look delicious but is poisonous, or that a stranger may seem nice but not be—is an essential life skill.

How Children Learn Language
In the first of a string of studies, Ellen Markman (publishing in 1984 with Jean Hutchinson) showed preschoolers a picture of an object (a dog, say). Then they were shown a picture of something thematically linked to the first picture (a bone) and something taxonomically similar (a cat) and asked to choose which was similar to the first picture. When asked just to find something similar (“See this? Find another one.”), they would generally select the bone. But when the first object was given a novel name (“See this fep? Find another fep.”), they would choose the cat. Markman suggested that this strategy of limiting meaning of new nouns to refer to categories (the “taxonomic assumption”) considerably simplifies for children the problem of learning language. This idea ran counter to conventional theory, which had held that children generally classify thematically.

Marshmallow Matters
Between 1968 and 1974, Walter Mischel conducted a series of studies on what makes it hard or easy for children to delay gratification. Children were offered more of something they were known to want (two marshmallows rather than one, for example) if they were able to wait for the researcher to leave and then return to the room. Mischel varied the rewards and experimented with keeping them visible or hidden. He found that hiding them made it easier to wait, as did offering the children suggestions for how to distract themselves. The results deepened our understanding of the nature of willpower.

Moreover, by showing how thinking can change the manifestation of personality (in this case impulsivity), Mischel’s experiments supported his “social-cognitive” approach to personality. This challenged Freud’s classic psychoanalytical approach, which saw personality as rooted in instinctual drives and wishes.

In follow-up studies, Mischel found that children better able to develop strategies for delaying gratification spontaneously at ages 4 and 5 became more educationally successful and emotionally intelligent. “These delay abilities seem to be a protective buffer against the development of all kinds of vulnerabilities later in life,” he concluded.

More than three decades later, Mischel continues to follow up with the Bing group—and hopes any Bing alumni with whom he’s lost touch will contact him at Columbia. They are, he says, “a very special group in the history of social science.” His latest follow-up, launched with Oslem Ayduk at UC-Berkeley, examines the ability to delay gratification in a new generation: the Bing alumni’s own preschoolers.