Parents, take note! Your one-year-old baby's ability to group objects according to the names associated with them - as opposed to their appearance alone - offers a glimpse into how their vocabulary will develop by the time they are 18 months, a new study has found.
"Our findings offer one piece of the very large puzzle that is vocabulary development," said Brock Ferguson, lead author of the study and a doctoral candidate in cognitive psychology at Northwestern University in US.
"This is a big first step towards using these cognitive tasks to identify infants at risk for language delays," Ferguson said.
The study examined whether individual differences in the precision of 12-month-olds' ability to link language and object categories was related to both their present and future vocabulary growth.
Ferguson offers a real-world analogy to the situation researchers create in the lab to measure infants' use of names as a guide to object categorisation.
"Imagine you are taking your baby for a visit to the primate house at the zoo," he said.
"There are gorillas, chimpanzees and monkeys in the primate house. Although all the primates look fairly similar, but we know them to be different because we refer to them by different names," said Ferguson.
In that hypothetical scenario, 12-month-old babies who conclude that all of the primates belong in the same category, despite the fact that their mother has referred to each by a different name, tend to have a less developed vocabulary, according to Ferguson's findings.
"In our study, babies who went ahead and grouped objects together even though the researchers had labelled them with distinct names were later found to know fewer words," he said.
Cognitive development is broadly defined as the process by which babies and young children learn about the world around them, and includes the acquisition of problem solving, memory, perception and language.
Working at the Project for Child Development, leading developmental scientist Sandra Waxman and her colleagues have already shown that talking to young children, even before they can speak, strengthens their language and cognitive abilities.
"This new finding is the first to link infants' performance on our cognitive task to their progress in learning new words," said Waxman, a professor of cognitive psychology and a faculty fellow in the university's Institute for Policy Research.
The research appears in the journal Frontiers in Psychology.
