Spending a lot of time on the Web can have both negative and positive effects on young people, according to the latest research presented in a special issue of Developmental Psychology.

Examples cited by the researchers included the sharing of self-injury practices by some and the improvement of academic performance and health awareness by others.

"A major goal for this cumulation of research is to show the good and bad sides of the Internet as it relates to children," said coeditors of the special issue Patricia Greenfield, PhD, of the Children's Digital Media Center, University of California at Los Angeles and Zheng Yan, PhD, of the State University of New York at Albany.

In a series of six articles, leading researchers examine normal behavior in chat rooms and the use of message boards by adolescents who self-injure, uses of the Internet to improve academic achievement among low-income youth and ways to provide health information to youth living in developing countries.

The authors observed 406 message boards to investigate how adolescents solicit and share information related to self-injurious behavior. Females 14-20 years of age visited these bulletin boards the most.

The findings show that online interactions provide essential social support for otherwise isolated adolescents, but these online boards may also normalize and encourage self-injurious behavior and add potentially lethal behaviors to the repertoire of established adolescent self-injurers and those exploring identity options, said lead author Janis L. Whitlock of Cornell University.

The authors also found that Internet message boards provide a powerful vehicle for bringing together self-injurious adolescents. Although the message boards examined for these two studies may not be representative of all self-injury message boards, they do provide a snapshot of content and exchange common in those with high activity.

In the last five years, "hundreds of message boards specifically designed to provide a safe forum for self-injurious individuals have come into existence and may expose vulnerable adolescents to a subculture that normalizes and encourages self-injurious behavior," said Whitlock.

The Internet can also be a good educational tool for hard-to-reach populations.

Researchers from Michigan State University examined the positive effects of home Internet access on the academic performance of low-income, mostly African American children and teenagers involved in the HomeNetToo Project.

In this research, 140 children aged 1018 years old (83% African American and 58% male) living in single-parent households (75%) with a $15,000 or less median income were followed for a two-year period to see whether home Internet use would influence academic achievement.

The children who participated in the HomeNetToo project were online for an average of 30 minutes a day. Findings indicate that children who used the Internet more had higher standardized test scores in reading and higher grade point averages (GPAs) at one year and at 16 months after the project began compared to children who used the Internet less, said lead author Linda Jackson, PhD. Internet use had no effect on standardized test scores in math.

"Improvements in reading achievement may be attributable to the fact that spending more time online typically means spending more time reading," said Dr. Jackson. "GPAs may improve because GPAs are heavily dependent on reading skills," she added.

Between 75 and 90 percent of teenagers in the United States use the Internet to email, instant message (IM), visit chat rooms and explore other sites on the World Wide Web.