But Vishal and his family say two things changed around the seventh grade: his mother went back to work, and he got a computer. He became increasingly engrossed in games and surfing the Internet, finding an easy outlet for what he describes as an inclination to procrastinate.

“I realized there were choices,” Vishal recalls. “Homework wasn’t the only option.”

Several recent studies show that young people tend to use home computers for entertainment, not learning, and that this can hurt school performance, particularly in low-income families. Jacob L. Vigdor, an economics professor at Duke University who led some of the research, said that when adults were not supervising computer use, children “are left to their own devices, and the impetus isn’t to do homework but play around.”

Research also shows that students often juggle homework and entertainment. The Kaiser Family Foundation found earlier this year that half of students from 8 to 18 are using the Internet, watching TV or using some other form of media either “most” (31 percent) or “some” (25 percent) of the time that they are doing homework.

At Woodside, as elsewhere, students’ use of technology is not uniform. Mr. Reilly, the principal, says their choices tend to reflect their personalities. Social butterflies tend to be heavy texters and Facebook users. Students who are less social might escape into games, while drifters or those prone to procrastination, like Vishal, might surf the Web or watch videos.

The technology has created on campuses a new set of social types — not the thespian and the jock but the texter and gamer, Facebook addict and YouTube potato.

“The technology amplifies whoever you are,” Mr. Reilly says.

For some, the amplification is intense. Allison Miller, 14, sends and receives 27,000 texts in a month, her fingers clicking at a blistering pace as she carries on as many as seven text conversations at a time. She texts between classes, at the moment soccer practice ends, while being driven to and from school and, often, while studying.

Most of the exchanges are little more than quick greetings, but they can get more in-depth, like “if someone tells you about a drama going on with someone,” Allison said. “I can text one person while talking on the phone to someone else.”