Among the most poignant letters I receive as an advice columnist are those from lonely people. Here are some typical samples. The letters are real but I’ve changed names to protect privacy.

From May, a 14-year-old girl in middle school: “I used to have tons of friends in elementary school but now I only have three friends I’m close to. What’s wrong with me?”

From a new mom, let’s call her Angela: “I’m the first one in my group to have a baby. I can’t go out partying anymore. Actually, I don’t want to. But I’m losing my friends. My husband is terrific but he’s gone all day. The baby isn’t much of a conversationalist yet. What do you suggest?”

From a high school guy, Ron: “I know a lot of people but I don’t think I have a real friend. I mean, I help people out when I can and I’m on several teams but I don’t think there is anyone who would help me. Why can’t I connect?”

From Harvey, an 80-year-old man: “Most of my good friends have died. I never thought I’d be the last one standing. My kids are all too busy to want to come over very much. If it weren’t for the guy I play chess with, the only people I’d talk to all week would be the paperboy and the guy who gives me coffee when I go to the drive-through window. How does a person my age find new friends?”

Why are these people longing for connection when they are plenty busy? Because it’s a fact: People are social creatures. We need other people in our lives to feel most ourselves, to be happy and even to be healthy.

It’s no wonder that advice columnists like those of us on PsychCentral get so many letters asking what to do to find friends, keep friends and make better friends. People want more than just to get along. They want to feel connected — at least to a few people they can feel close to and with whom to share the events of their lives and their confidences.

Robin Dunbar, an evolutionary anthropologist in England, has made a study of how many people the average person knows. He and other researchers have found that on average people are connected in a variety of ways to a total of about 148 others. He rounds it to 150 for simplicity’s sake. It doesn’t matter if we’re talking about hunter-gatherer societies, businesses or Facebook, people seem to be able to connect with no more than about 150. Even those who claim to have 1,400 followers on Twitter or Facebook actually only consistently interact with about 150. (Dunbar theorizes it has something to do with our brain’s capacity, but that has yet to be tested.)

Dunbar isn’t suggesting we all need 150 friends. That’s the total number of all the different kinds of people with different levels of connection that we generally recognize as being somehow involved in our lives. Within that number are levels of connection that are important in different ways.

Imagine Dunbar’s theory as a target. You are in the bullseye. In the next circle out are the people who are most dear to you. On average, people have three to five close, personal relationships. That’s all. Those of you who worry that you only have a few close friends can relax. You are well within normal. Of course, an average is the midpoint of any group. So some people have more than three, some have fewer.

As you move out from the center, each concentric circle has more people but with less meaningful connection. After the close friend group, the next ring generally has about 15 people who matter — usually relatives, mentors, and friends who don’t quite make the inner circle but still mean a lot. We see them less often than those in the center group but the relationships are warm and reciprocal in some way. They are the kind of people who seem to be in ongoing conversations with us that are interrupted by long periods of silence. When we get together again, it’s as if we never left off.

The next ring has about 50 people, typically friends of friends we’ve gotten to know a bit and people we see regularly but don’t count as our own friends. Perhaps you’ve met them multiple times at a mutual friend’s parties. Maybe you’ve served on a committee with them but never followed up to get to know them better. Or perhaps they are the people we see regularly at our kids’ soccer games.

Finally, there’s an outer ring of other people we recognize by sight as part of our community but we don’t relate to much, if at all. They are the people we recognize when we see them in a crowded mall or say hi to when we bump into them at a concert. If you are at all active in your school or community, you may have more acquaintances than you think you do — probably a number that will bring your total of all the rings to about 150.

All of the rings in the circle are important. Feeling that we are at least recognized by a substantial number of people in our community or school (whether the paperboy, the barista at the coffee shop, the cafeteria lady or the school crossing guard, for example) is part of what makes us feel at home. Having a few folks in that innermost circle of intimacy is what makes us feel valued and loved. I’m betting that, if pressed, Ron, Harvey and Angela can identify a number of people in most of the outer circles. Their problem is the lack of enough people in that first circle.

Feeling lonely when the population in the inner circle dips below two or three is normal and appropriate. That feeling of loneliness is a signal from our inner wise self that we need to do something to reconnect to feel good. We don’t need a ton of friends but we do need a few. We don’t need to sit at the metaphorical popular table but we do need to have connections within our community or school.

Fortunately, other people need friends too. The trick is finding each other. That inner group of people isn’t going to come knocking on the door. The key to getting connected is getting active.

Sometimes all it takes is making the time to bring people from one of the outer circles inward. An invitation to have coffee, to attend a community event or to go for a walk is all that’s required to set things in motion.

Sometimes connecting requires us to actively, purposefully set out to meet new people by doing new things. Sometimes it takes the willingness to risk rejection by trying to get to know a particular person better.

Let’s go back to our letter-writers. Harvey, for example, could expand his circle through his passion for chess. He might ask his chess partner to be sure to introduce him to some other chess players he knows. Or maybe he could volunteer to start or help with a local chess club.

Angela needs other new moms to talk to. If she asks around, she might find that there is already a social group for young mothers in her town. If not, she could start one. She’ll quickly find that she’s not alone. Most new mothers are hungry for the support that comes with connecting to others whose kids are in the same life stage. What starts as a support group of strangers often evolves into a group of lifelong friends.

Ron has plenty of people in outer circles. He needs to take some steps to bring some people in closer. He already has much in common with other guys so he could reach out to those he likes best. He could ask teammates to go for a soda after a game, or to watch an important game on TV. He could ask someone whose skills he admires to stay after practice to give him some pointers. It would be a start.

As for May, she needs to relax. Kids change as they mature so it’s not at all unusual for some elementary school friends to drop away. Now in middle school, she already has three important friends. If she wants more, she could encourage her group to get involved with activities at school. That would add people to Dunbar’s outer circles – the very people who might naturally become part of her inner group.

By gathering up a bit of courage and daring to take action, acquaintances can become friends and new people can be added to our friendship circle. As poet William Butler Yeats said, “There are no strangers here; only friends you haven’t yet met.”

For more detailed advice about how to make new connections, see Dr. Marie’s book, Unlocking the Secrets of Self-Esteem.

Chess player photo available from Shutterstock