Chicago ? Too much TV-watching can harm children’s ability to learn and even reduce their chances of getting a college degree, three new studies suggest in the latest effort to examine the effects of television on kids.

Critics faulted the research for not adequately considering the content of the TV watched, but experts said it bolsters advice that children shouldn’t have TVs in their rooms.

The separate findings were published Monday in the July issue of Archives of Pediatrics & Adolescent Medicine.

One of the studies involved nearly 400 northern California third-graders. Those with TVs in their bedrooms scored about eight points lower on math and language arts tests than children without bedroom TVs.

A second study, looking at nearly 1,000 adults in New Zealand, found lower education levels among 26-year-olds who had watched lots of TV during childhood.

A third study, based on nationally representative data on nearly 1,800 U.S. children, found that those who watched more than three hours of television daily before age 3 scored slightly worse on academic and intelligence tests at ages 6 and 7 than youngsters who watched less TV. The effect was only modest but still worrisome, said co-author Frederick Zimmerman, a researcher at the University of Washington.