Is our technology replacing our identity?

After publishing an optimistic book about the internet in 1995 ("Life on the Screen"), MIT social science professor Sherry Turkle has now written a darker tome, "Alone Together,"  worrying that we are moving more of our lives online and away from real physical human contacts. The first half of the book is about social robots. From Jonah Lehrer's review:

“Dependence on a robot presents itself as risk free,” Turkle writes. “But when one becomes accustomed to ‘companionship’ without demands, life with people may seem overwhelming.” A blind date can be a fraught proposition when there’s a robot at home that knows exactly what we need. And all she needs is a power outlet...The reason robots are such a slippery slope, according to Turkle, is that they take advantage of a deeply human instinct. When it comes to the perception of other minds, we are extremely gul­lible, bestowing agency on even the most inanimate of objects.

The second part of the book deals with Turkle's concern that the internet is becoming our way of being with other people, in a style that turns them into objects. (Why did I just text my friend instead of actually just calling and talking with him.)

...the online world is no longer a space of freedom and re­invention. Instead, we have been trapped by Facebook profiles and Google cache, in which verbs like “delete” and “erase” are mostly metaphorical...We aren’t “happy” anymore: we’re simply a semicolon followed by a parenthesis. Instead of talking on the phone, we send a text; instead of writing wistful letters, we edit our Tumblr blog...these obvious objections shouldn’t obscure the real mystery: If the Internet is such an alienating force, then why can’t we escape it? If Facebook is so insufferable, then why do hundreds of millions of people check their page every day?

My own experience is that my participation in social web sites has broadened my world of real world contacts and friends, as noted by Lehrer:

...despite our misgivings about the Internet, its effects on real-life relationships seem mostly positive, if minor. A 2007 study at Michigan State University involving 800 undergraduates, for instance, found that Facebook users had more social capital than abstainers, and that the site increased measures of “psychological well-being,” especially in those suffering from low self-esteem. Other studies have found that frequent blogging leads to increased levels of social support and integration and may serve as “the core of building intimate relationships.” One recurring theme to emerge from much of this research is that most people, at least so far, are primarily using the online world to enhance their offline relationships, not supplant them.