Mexican American preschoolers lag their white counterparts in early language and pre-literacy skills, but are equal in social skills, according to new research from the University of California, Berkeley, and UCLA.

In a report published in the Maternal Child Health Journal, the researchers cautioned teachers, pediatricians and other health care providers to "not assume social-emotional delays, even when language or cognitive skills lag somewhat behind."

The research team -- comprised of research pediatricians, psychologists and a sociologist -- also suggested that health practitioners might take particular note of social and emotional delays when they do arise with Mexican American children, given the youngsters' generally robust development in that area.

Experts attributed the gap to poverty rates and exposure to books at home.

The researchers found that nearly half of Mexican American and other Latino children they studied were read to once a week or less. Just 14 percent of all white parents read to their children that infrequently.

Thirty-seven percent of Mexican American families in the study sample of 4,700 children nationwide lived below the federal poverty line, compared with 10 percent of white families.