Studies find Latino toddlers' gap in cognitive growth
| 20 October 2009
BERKELEY — Two new studies led by University of California, Berkeley, researchers find that immigrant Latina mothers, who typically live in poor neighborhoods, give birth to healthy babies, but their toddlers start to lag behind middle-class white children in basic language and cognitive skills by the age of 2 or 3.
The findings, based on a nationwide tracking study of 8,114 infants born in 2001, appear this week in the Maternal and Child Health Journal, and a companion report will be published this winter in the medical journal Pediatrics. The researchers are based at UC Berkeley's Institute of Human Development, UCLA's School of Medicine and the University of Pittsburgh Medical Center.
The UC Berkeley-led researchers report that Latina mothers from the poorest group studied - those of Mexican heritage, who speak Spanish rather than English at home, and who are least acculturated - give birth to healthy babies whose weight equals that of the average newborn of middle-class, non-Latino white mothers. These women also are no more likely than white mothers to give birth prematurely, which can jeopardize the early brain growth of infants.
The Mexican American mothers "display remarkably sound prenatal practices and healthy diets, more beneficial habits than any other group in the U.S.," said Bruce Fuller, a professor of education and public policy at UC Berkeley, who led both studies. He noted that pregnant Latina women also smoked and drank alcohol far less than their African American and white counterparts.
But while robust births contribute to the earliest cognitive growth of Latino toddlers, Fuller said these youngsters are falling behind the pace of white children's language and mental development by the time they turn 2 or 3.
Basic cognition proficiencies for infants at 9 to 15 months of age - such as comprehending their mother's speech and beginning to use their own words and gestures -were found to be statistically equal between Latino and white children, said Fuller. But by 24- to 36-months of age, Mexican-American toddlers lag their white counterparts by up to a half-year in terms of word comprehension, speaking with varying complexity and working with their mothers on simple learning tasks as assessed in English or Spanish, the researchers found.
The study team points to low levels of maternal education, larger family size, and uneven learning practices in the home to explain their findings. Just one-fifth of Mexican American and one-third of all Latina mothers had completed any college courses, compared with almost two-thirds of white mothers. Almost three-fifths of Mexican American toddlers were growing up in families earning less than $25,000 per year, relative to just one-fifth of white families.
"The great majority of young Latino children benefit from two warm and caring parents at home," Fuller said. "But the reading activities, educational games, and performing the ABCs for Grandma, so often witnessed in middle-class homes, are less consistently seen in poor Latino households."
The study also identifies assorted factors contributing to the health and mental growth of all toddlers, regardless of their ethnic and class origins. For example, they found that:
- Female toddlers fare better overall, displaying stronger linguistic and cognitive gains between 9 and 30 months of age, compared with boys.
- Toddlers with employed mothers show significantly stronger mental development than those raised by stay-at-home mothers, even after taking into account maternal education and family income.
- Early cognitive growth is limited in families with more children in the home.
- Toddlers who were not breastfed, along with male toddlers, are more likely to show early signs of childhood obesity.
- Toddlers whose mothers had received fertility treatments fared no better or worse than others.
Fuller said the results involving Latino mothers and children may inform the debate over President Obama's move to strengthen aid for young families with infants or toddlers through his economic stimulus package. It expands by about $3 billion both Head Start preschools and the newer Early Head Start program. These programs are designed to improve the care of infants and toddlers in low-income neighborhoods.
Last month, the U.S. House of Representatives authorized spending $8 billion in early childhood challenge grants to encourage states to broaden early childhood care and education, and that plan moves to the U.S. Senate floor next. Meanwhile, Obama is pushing for a new home-visiting program with congressional health care legislation that would send trained professionals into the homes of expectant mothers to improve prenatal practices and infant development.
By 2025, three in 10 children in the United States will be of Latino descent, according to a report issued in May by the Pew Hispanic Center. Just under half of all Latino children immigrated to the United States or were born here.