Facebook Inc., Skype Technologies SA and Google Inc. logos are displayed on a computer screen for a photograph in New York, U.S., on Thursday, May 5, 2011. (Jin Lee/BLOOMBERG)

There is a simple premise at the root of The Great Social Experiment: What would it take for each and every one of us, as addicted as we are to our virtual Facebook relationships, to uproot our entire social identity and migrate it to a new Web site? Google is attempting to do just that with innovative features like Huddles, Circles, Sparks and Hangouts. It’s the equivalent of asking a parent to pack and move a family to a completely different city to pursue an attractive new job opportunity, while leaving behind a host of unanswered questions: What happens to the friends who remain behind? How soon will you meet other friends in your new city? What if the grass really is not greener on the other side?

Google’s earlier U.S. social experiments – Orkut and Buzz – fell flat for various reasons. (Although Orkut is still big in Brazil and India.) Buzz was deemed too social – the flow of information through the social network felt like trying to drink through a fire hose. But it appears that Google+ has legs. Have you noticed that Google+ invites are still going like hot cakes? Idealab founder and CEO Bill Gross estimates that Google+ may already have 4.5 million users after just a week of invitations.

At the end of the day, the ultimate success of Google+ will not be due to superior technology. It will be due to a superior knowledge of sociology and psychology. In short, it will be due to knowing more about us as The Social Animal. We may be able to lie to ourselves, but it is practically impossible to lie to Google AdWords.

The sentiment is that Google has taken everything that’s wrong with Facebook — like over-sharing to all of your friends — and fixed it. Even Mark Zuckerberg seems concerned that Google+ may have stolen a march on Facebook just before his big IPO payout. Has Google devised an ingenious system of triggers and nudges (sorry, another sociology term) to convince us all to make the switch? All of us, to one degree or another, would love to press “reset” on our social lives. At least, that’s the big bet in Mountain View. (Washington Post Co. Chairman and chief executive Donald E. Graham is a member of Facebook’s board of directors.)