Characters are never alone. You ever notice that? Abbot had Costello, Lucy had Ricky, Holmes had Watson, and Gilligan had The Skipper. Why is this? Psychologically it’s because people are social creatures. We go better together. Some part of us needs to be able to share our thoughts and feelings with others. But as writers, we create sidekicks and foils because relationships are a marvelous tool for revealing your characters.

Even characters who seem alone, aren’t. There’s always a sidekick, even if it isn’t human. Tom Hanks, in Cast Away, had his volleyball. Bruce Dern’s character in the Sci-Fi classic Silent Running had three cute little robots with him. And of course, Keir Dullea’s murderous computer nemesis in 2001: A Space Odyssey needs no explanation at all. Those characters’ sidekicks weren’t people, but they still provided a relationship that revealed a lot about the character.

You could probably write a whole book on this, but let me instead just give three highlights, three quick methods for using relationships to show what kind of people your characters are.

Use shared or borrowed goals

Any time you have one character seeking to enter the good graces of another, it can work well to have that character adopt as his own something that is a goal for the other character. You might have your love-struck hero take up volunteering at an animal shelter, because he learns that the girl he’s sweet on has a soft spot for homeless animals. He might even adopt a sad, mangy dog, despite his own allergies (they’ve got pills for that, right?) just to impress her.

Although this technique is particularly apt for unrequited love, it works for other situations too. Not long ago, I finished Michael Snyder’s book Return Policy, in which there’s a sub-plot about one character seeking to land a promotion by voluntarily taking on a tedious, boring data entry job that everyone else in her office has been avoiding. It means longer hours, time away from her son, but she knows it will make her manager look good and hopes it will tip the scales toward her.

Let relationships reveal deeper motivations

Relationships always have levels to them. For example, you might have a character who is always creating little competitions between himself and his friends. His notion is that he’s creating opportunities for fun and that this will make people like him. How he reacts says a lot: is he gracious in victory and defeat, or obnoxious in victory and a sore loser to boot? How his friends react should be very telling, too: are they in fact having fun, or are they annoyed? It’s this interaction between the characters that is your vehicle for showing the primary character’s competitive streak. How the relationship plays out on the page says everything.

Or going back to the love-struck mangy dog owner, while that behavior may seem sweet and fawning at first, there’s a darker side lurking underneath. It is ultimately selfish: he doesn’t actually care about the dog, except to the extent that the dog can help win him the girl. And how disrespectful he must be of her, if he thinks she’s dumb enough to be manipulated in that way, or that she won’t see right through him. Does he even actually love her for herself? If he’s so willing to alter his outward image—and mask his inward nature—to impress her, perhaps he is more attracted to his outward image of her than to the person she is underneath.

The levels inherent in any relationship are a great source of surprises. Affection can mask selfishness. Competition can mask self-importance. Actions that seem driven by one motive can, in fact, be hiding a deeper and completely opposite motive. Revealing those deeper motives can make for wonderful dramatic reversals. It’s the best way to surprise a reader, by letting them learn something new about your characters that they didn’t necessarily expect.

Show multiple points of view

Finally, as I wrote last month, nobody sees themselves the same as other people see them. If your story has multiple POV characters, you can readily exploit this to show the contrast. For example, the competitive boy sees his competitive habit as an attempt to create fun between himself and his friends. But his friends, who have grown weary of seeing who can throw a crumpled napkin into the trash can from the farthest away, see it as something else: annoying egotism.

There’s an opportunity with multiple POVs, though, that goes deeper than simply showing a contrast between some character’s self-opinion and how others see him, and it’s one you shouldn’t miss out on. Try to show the contrast in a way that creates mystery rather than solves it. That is to say, when you’re done showing both parties’ view of the situation, have you left the reader wondering who is right?

If so, you have a wonderful opportunity to also create a great dramatic reversal: Solve the mystery a few chapters later by springing yet another layer on the reader, revealing that nobody is right! Reveal that he’s not as fun-loving as he thinks he is, but neither is he as egotistic as his friends think. Rather, they’re both wrong: deep down he’s just insecure. Beyond the fun-and-games facade, underneath the ego, he creates all these competitive situations because really he’s struggling to reassure himself of his own abilities.

It’s not a meaningless reversal, of course. It’s not there just to keep the reader guessing. To really work, it had better be part of a meaningful character arc. But I hope that at least gives you gives a taste of how these strategies—just like people—go better together than alone.