Something about the Internet causes many of us to lose our inhibitions. We willingly get into vicious flame wars with total strangers. We help other strangers with information, contacts, and advice that we might never offer if we met them in person. We strike up friendships and romances via e-mail that can be emotionally more intense and involving than our relationships in the offline world. And some of us become so attracted to online realms that we spend more and more time there, increasingly isolating ourselves from our daily responsibilities.

The reasons for these reactions still are not fully understood, says Patricia M. Wallace, author of "The Psychology of the Internet" (Cambridge University Press, $24.95, hardback). "The Internet explosion happened so rapidly," she writes, "that we have not had much time to step back from the medium and look at it more systematically, as a new environment that can have potent effects on our behavior."

But the current research on Internet users can be combined with what we already know about human reactions in other settings. From there, we can draw "meaningful parallels" that give us important insights into why we behave as we do on the Net, she contends.

Her well-written book delves into a variety of social and cultural aspects of the Internet and how they seem to affect us psychologically. Not only do individuals behave differently online, but traditional group dynamics also tend to take on new dimensions.

In cyberspace, she points out, "the cues you use to form impressions, and the tools you use to create your own [impressions on others], are quite different than they are in real life." (For the sake of her discussions, she defines "real life" as "anything and everything that is not on the Net.")

"The Psychology of the Internet" is an important book for individual Web surfers, but it should be particularly enlightening to those who manage electronic work groups, chat rooms, bulletin boards and other online facilities where many users gather--and squabble.

One of the best chapters deals with the Internet as a "time sink" and why it can be "psychologically so compelling that some people seem barely able to log off. Preliminary research suggests that greater Internet use is associated with increases in loneliness and depression, and also reductions in family communications and social involvement." This should raise warning flags, she says, "as we invest heavily to wire every home, classroom, and business."

Her recommendations for the future, unfortunately, are vague. But she sees great hope for the wired world if we take greater responsibility for our online behavior.

"If there is worthwhile life on the net," she writes, "then we are part of that life and we may be in a position to guide this technology and what happens inside of it." In her view, we still have "both the power and the responsibility to influence what happens on our global commons."

Si Dunn and Connie Dunn