Researchers define infants’ quantitative abilities, find flaws in earlier research on development

Susan Levine, Professor in Psychology and one of the co-authors of Quantitative Development, works with a young toddler in a counting exercise

Although many people would like to think their babies are bright enough to count before their first birthday, and some child psychologists have suggested they can, this possibility is disputed in the results of a 10-year evaluation by leading scholars at the University.

“Earlier claims of infants’ quantitative skills are greatly exaggerated,” said Janellen Huttenlocher, the William S. Gray Professor in Psychology and an author of Quantitative Development in Infancy and Early Childhood. “Infants start with only a crude awareness of amount, which slowly evolves into an ability to distinguish between numbers of discrete objects.”

Co-authors Huttenlocher, Susan Levine, Professor in Psychology, and Kelly Mix, a professor at Indiana University, carried out several studies that led to this conclusion. In its review, the Chicago team found significant flaws in earlier research. The so-called “natavist” view, which gained wide acceptance among developmental psychologists, contrasted significantly with an earlier view by French psychologist Jean Piaget, which demonstrated that children do not develop quantitative competence until after age 5.

“Neither the natavists nor Piaget was right,” said Levine.

The researchers found that infants, contrary to natavist claims, do not have an innate ability to distinguish between discrete objects, nor can they recognize what is numerically equivalent. During the first months of life, they can, however, discriminate between the “amount of stuff,” said Levine, adding, “an infant can recognize quantity based on amount, but not on number.”

For instance, an infant can distinguish between six elephants and six ants because the amount of six elephants is vastly different from the amount of six ants. But an infant could not distinguish between something that is the same in total amount but not in number. For example, Levine explained, an infant could not distinguish between one full chocolate bar vs. the 12 pieces it could be divided into.

The researchers also found that toddlers and preschool children have far more advanced skills than previously believed by Piaget. Toddlers between 2 1/2 to 3 1/2 years old begin to move beyond the ability to distinguish amount and start to distinguish between numbers of discrete objects. Some children as young as 3 years old exhibit nonverbal math skills, comprehending quantity and performing simple addition and subtraction using groups of objects.

“Children bring far more mathematical understanding to preschool than parents and teachers realize,” Levine said. “Because a preschooler’s verbal understanding of conventional math terms is limited, the ability to comprehend quantitative concepts is often overlooked.”

Though the new book was aimed at an academic audience, it has important lessons for parents readying their children for kindergarten, Huttenlocher said, because “it demonstrates that preschoolers have an abstract understanding of numerical knowledge before they develop the language skills necessary to articulate that knowledge.”

As a result of this finding, Huttenlocher urges parents to “teach children to label quantity. When you’re setting the table, count out the number of forks. OneÖTwo.. Three. Children may understand quantity, but they need the language to begin conventional math learning.”

The impetus for Quantitative Development, Huttenlocher said, was a general skepticism about natavist claims, specifically a finding that showed that 7-month-old infants could recognize numerical equivalence.

For example, it was claimed that infants could recognize that a set of two apples is equivalent to a set of two honking sounds because both contain two items. In their own experiments, the University researchers had found that even 3-year-olds had trouble recognizing numerical equivalence across such diverse sets as objects and sounds.

“It just didn’t make sense,” Huttenlocher said. The experiment was replicated at Chicago, and in each instance, the original results could not be confirmed. Identifying a possible flaw in earlier claims spurred Huttenlocher, Levine and Mix to revisit further demonstrations of number awareness in infants, and ultimately, to demonstrate that early quantitative sensitivity consisted of a sense of amount and not number.

Levine and Huttenlocher are researchers with the Center for Early Childhood Research, which receives funding through a grant from the Robert R. McCormick Tribune Foundation.