IStock Photo 12584795 © Drew Hadley

The Beatles sang, “I get by with a little help from my friends,” and they were right—friendship is as basic a human requirement as eating and sleeping. Feelings of social isolation are linked to a vast array of human ills, from increased cardiovascular risk factors in young adults to the progression of Alzheimer’s disease in older people.

Thankfully, most of us are not so isolated. The odds an adult reports having zero close friends are 1 in 50, while the odds an adult reports having 10 or more close friends are 1 in 3.7.

But sometimes modern life puts up roadblocks to optimal health. If fast food is making us unhealthy eaters, and stress is making us poor sleepers, it seems logical to ask: Is the popularity of social networking making it more difficult for us to connect with people in the real world?

Having close friends is directly related to our level of happiness. One study found that half of people with between five and ten friends reported being happy, while people with fewer friends had a 60% chance of being unhappy. In general, people who said they were “extremely satisfied” with their lives had twice the number of friendships as those who were “extremely dissatisfied.” And this really shouldn't be surprising news to anyone, since the odds a person feels his or her relationships with friends bring happiness are 1 in 1.1 (91%).

And while loneliness has been found to be contagious, happiness is as well. Research at Harvard Medical School has found that even a very indirect association with happy people—having a happy friend of a friend of a friend—increases your own chance of happiness by about 6%.

But what about those really indirect friends—and by that we mean the virtual ones? Is making a friend you have never met, but who shares your love of online Scrabble, the same as making a “real” friend? Or is the Internet actually destroying our chance at real happiness?

As it turns out, not by a long shot. In fact, contrary to the picture of the lone, pale Internet user, online all day typing to strangers and cut off from physical society, social network users actually spend more time socializing with friends and family and participating in local communities. And as for those virtual friends, adding more of them actually increases our social world, allowing us to communicate with people we might not otherwise talk to. Bloggers are much more likely to share confidences with someone of a different race than they would if they were face-to-face. People who share online photos are more likely to have discussions with a person who belongs to another political party. In sum, people who have active online relationships have a more diverse and robust total social network than those who limit their friendships to the physical world.

Of course, just because we have 500 “friends” on Facebook doesn’t mean we connect with all those people the same way we connect with actual friends. Facebook’s own research found that the average male Facebook user with 500 friends leaves comments on only 17 of his friends’ pages, and engages in two-way communication with only ten friends. For a woman with the same number of Facebook friends, the numbers are only modestly higher—she leaves comments for 26 friends, and chats with 16. As BusinessWeek reported, “People don't pay much attention to most of their online friends.”

And that’s what it comes down to. Social networking isn’t usurping traditional friendships—it’s merely enhancing the basic human need to reach out and connect. We can share a great piece of news with our 500 Facebook friends—but we’ll still go out to celebrate with our five best buddies.