Babies are born accountants. They can estimate quantities and distinguish between more and less. Show infants arrays of, say, 4 or 12 dots and they will match each number to an accompanying sound, looking longer at the 4 dots when they hear 4 sounds than when they hear 12 sounds, even if each of the 4 sounds is played comparatively longer. Babies also can perform a kind of addition and subtraction, anticipating the relative abundance of groups of dots that are being pushed together or pulled apart, and looking longer when the wrong number of dots appears.

Babies are born Euclideans. Infants and toddlers use geometric clues to orient themselves in three-dimensional space, navigate through rooms and locate hidden treasures. Is the room square or rectangular? Did the nice cardigan lady put the Slinky in a corner whose left wall is long or short?

At the same time, the Spelke lab discovered, young children are quite bad at using landmarks or décor to find their way. Not until age 5 or 6 do they begin augmenting search strategies with cues like “She hid my toy in a corner whose left wall is red rather than white.”

“That was a deep surprise to me,” Dr. Spelke said. “My intuition was, a little kid would never make the mistake of ignoring information like the color of a wall.” Nowadays, she continued, “I don’t place much faith in my intuitions, except as a starting place for designing experiments.”

These core mental modules — object representation, approximate number sense and geometric navigation — are all ancient systems shared at least in part with other animals; for example, rats also navigate through a maze by way of shape but not color. The modules amount to baby’s first crib sheet to the physical world.

“The job of the baby,” Dr. Spelke said, “is to learn.”

Role of Language

More recently, she and her colleagues have begun identifying some of the baseline settings of infant social intelligence. Katherine D. Kinzler, now of the University of Chicago, and Kristin Shutts, now at the University of Wisconsin, have found that infants just a few weeks old show a clear liking for people who use speech patterns the babies have already been exposed to, and that includes the regional accents, twangs, and R’s or lack thereof. A baby from Boston not only gazes longer at somebody speaking English than at somebody speaking French; the baby gazes longest at a person who sounds like Click and Clack of the radio show “Car Talk.”

In guiding early social leanings, accent trumps race. A white American baby would rather accept food from a black English-speaking adult than from a white Parisian, and a 5-year-old would rather befriend a child of another race who sounds like a local than one of the same race who has a foreign accent.