A language gap between low-income children and more affluent ones opens up as early as 18 months, according to new research from Stanford researchers led by Anne Fernald that was just published in Developmental Science. At that age, disadvantaged toddlers are several months behind their better off peers in language proficiency.
For her research, Fernald first conducted an experiment with 20 18-month-olds who lived near Stanford to see how quickly and accurately they could identify objects after being prompted verbally, measuring down to the millisecond. She then took the experiment to a city north of the campus where average household income and education levels are much lower, recreating the experiment with 28 other toddlers. Both groups were retested six months later and parents were also asked to report on their vocabulary growth.
Her findings show that the children from wealthier and better educated backgrounds were 200 milliseconds ahead of the lower-income kids. While both groups improved over time, at two years old the low-income children were barely at the level that the wealthier kids had reached at 18 months. Parents also reported a big vocabulary gap: high-income toddlers added more than 260 words to their vocabulary over those six months, while low-income ones learned 30 percent fewer words. “By 2 years of age, these disparities are equivalent to a six-month gap between infants from rich and poor families in both language processing skills and vocabulary knowledge,” Fernald said.
Past research has shown that children in higher-income and more educated households will hear 30 million more words by age three than those from low-income ones. That research points to differing levels of language stimulation that parents give their children. “For lots of reasons, there is generally less supportive talk to children in families living in poverty, which could partially explain the SES [socioeconomic status] differences we found in children’s early processing skill and vocabulary learning,” Fernald said.
The research comes just days after other data showing that in 17 states, the majority of public school students are poor. Child hunger is so rampant that three-quarters of the country’s teachers report that it is a serious problem in their classrooms. It is also clear that poverty takes other tolls on children’s mental development: Growing up in poverty has been shown to change a child’s brain in ways that can harm emotional processing, increase the risk of mental health problems, and even raise mortality rates. It also harms their development of working memory.
In order to combat these early effects that leave low-income children struggling to keep up academically later in life, many have been pointing to expanding access to high-quality child care and preschool. Currently, just 51 percent of three-year-olds and 69 percent of four-year-olds are enrolled in preschool programs, putting the United States at number 24 and 26 globally, respectively. President Obama has proposed a plan for universal preschool, which uses an increased tobacco tax to pay for expanded access.