“Daddy, can we have our little talk now?” seven-year-old Zachy will ask in his small raspy voice right before bedtime. This is our special time together — just the two of us. We get all cozy underneath his blanket and trade stories about our days at school and work, him telling me about his meetings and deals, me telling him about recess and the snacks I traded for at lunch. Tonight, though, I need Zachy to help me with my homework — a story I’ve been assigned to write about him.

“About me?” he asks, all lit up as if I’d just handed him a bag of Hershey’s Kisses.

“Yeah, what should I say about you?”

“That I’m funny, that I’m cute, that I’m crazy, that I pick my nose, that I always have stuff in my toes from my socks,” he says excitedly and then adds, “and that I love my brother.”

It doesn’t seem to matter that no less than five minutes ago, his brother — who outsmarts him by a year-and-a-half — was beating the heck out of him. It doesn’t seem to matter that his brother had the audacity to kick Zachy out of his own room. It doesn’t seem to matter that from the day Zachy was born, his brother has always come first. And it doesn’t seem to matter, Zachy will tell you, that his older brother is adopted.

Of course, that’s the reason it matters more than anything.

Zachy — adorable, bright, funny and sweet as he is — has always come second. We’d like to think this is purely about age, the lot in life of the younger sibling, but it’s more than that. When we adopted Robbie as a newborn eight-and-a-half years ago, it was the culmination of inconceivable perseverance (no pun intended): We’d been trying to have a biological child for four-and-a-half years.

In turn, Zachy’s conception and birth was as shockingly wonderful as walking into your own surprise party. Robbie was a gift we worked hard for. Zachy was a gift we received. And it’s this basic difference that has always separated the two of them — even, at one time, in my heart. For months after Zachy was born, it was a strange point of pride with me that I felt more strongly about Robbie than I did toward my own flesh and blood. But that is no longer how I feel. I love both of my sons the same, but different.

I love the way Zachy barrels out of bed each morning, ready for some great new adventure. I love the way Robbie throws his arms around me and won’t let go. I love the way Zachy twirls around the house and acts like Jim Carrey. I love Robbie’s unselfishness and tenderness. I love Zachy’s uninhibited laughter and independence. I love Robbie’s shyness and vulnerability. I love Zachy because he is a part of me. I love Robbie because he is a part of me I didn’t know I had.

They’re in love with each other, too, and dance the typical big-brother little-brother two-step, which is to say they’re at each others’ throats regularly. But Zachy also recognizes that Robbie is different. “I’m younger, he’s older. I’m taller, he’s shorter. I’m nicer, he’s meaner,” he explains in his inimitable style. “We have different voices and different-color hair and different-color eyes. I like basketball and he doesn’t.”

Zachy is the little brother, but is already bigger than Rob. Yet Robbie knocks him around like one of his stuffed animals and Zachy takes his licks accordingly because he doesn’t yet know that he doesn’t have to. It’s just not in Zachy’s nature to fight back. Or is it something else? Zachy is the little brother — and in many ways, he will always be — but he often acts more like the older sibling. He seems to know instinctively some things about their disparity, but doesn’t yet know how to express it in words. Zachy knows, for example, that he is somehow more secure than Robbie, and for good reason.

Not only does Zachy realize all of this about his older brother, he willingly accepts it. He knows Robbie needs him more than he needs Robbie, and he’s generally happy to be needed. Zachy also knows that his brother needs us in a way he never will.

I’m reminded of this distinction every morning as soon as I get to work. A photograph of each of my sons sits on my desk, and Zachy’s smile is the first ray of light that greets me before I get my coat off. It’s eclipsed a moment later, however, by the nearby photo of Robbie, struggling to fake a cheesy grin.

As hard as we try to treat them as equals, Robbie always seems to be a little more equal than Zachy. Is it just a question of their personalities? Robbie can be terribly stubborn, while Zachy is adaptable. Robbie will often freak out over the smallest detail, so we’re more inclined to say “no” to Zachy because we know he’ll handle it, and “yes” to Robbie because we know he won’t.

Nowhere is this inequity more apparent than in the way we discipline them. I find it much easier to yell at Zachy. At first I thought it was because he was stronger and could take it better — like Timothy Hutton’s character in Ordinary People — but the real reason is more obvious. I don’t want to hurt Robbie any more than he already has been hurt. Not being adopted somehow gives Zachy an emotional edge — a sense of confidence Robbie may never have. Zachy doesn’t have the unanswered questions Robbie will always carry around with him. Zachy will never struggle to answer some nice lady’s asking, “Where did you get that blond hair from?” Zachy is connected to us in a way that Robbie can never be, so we overcompensate on Robbie’s behalf. And although Robbie knows we love him, there’s still a small part of him that remains uncertain.

Which has a big effect on Zachy. Robbie craves our constant attention, our unending reassurances, our eternal patience; and, because of these daily requirements, he tends to monopolize a great deal of our time. This can be draining on all of us, and it should therefore come as no surprise that we sometimes wind up taking Zachy for granted.

We often joke that Zachy’s infancy went unnoticed, other than the fact that he looked like Manuel Noriega when he was born. We have hours and hours of videotape of Robbie as a baby, a handful of isolated minutes of Zach on his first few birthdays. In many ways, this seems typical of the whole second-child syndrome. The thrills of all the “firsts” — smiles, words, steps — are slightly diminished the second time around, and having two babies at the same time doesn’t always allow you to enjoy either one of them.

Zachy has invariably been a headliner trapped inside the skin of a second banana. He was reading when he was three, is an excellent artist and athlete, has an uncanny ability to figure out jigsaw puzzles and also happens to be very funny. He achieves without seeming to try very hard, much in the same way he came into this world. Whether he’s winning a drawing contest in kindergarten or gathering stripes in rapid succession in his karate class, we always react to his achievements in an almost nonchalant manner. As pleased as we are, we’re always aware of how our adulation will affect Robbie, who struggles at schoolwork and sports. Instead of giving Zachy his due, we low-key it because we don’t want Robbie to feel bad, we don’t want Robbie to think we love him any less or more based on what he does or doesn’t do. And, of course, we totally overreact about anything Robbie attains, which is unfair and downright confusing to Zach.

Until recently, the only dismay Zach ever showed about perpetually standing in Robbie’s shadow was his propensity for crying. Zachy often sounds like his heart is being cut out when Robbie commits the horrible crime of, say, calling him a “chicken” and buk-buk-buk-buking at him. Zachy knows we’ll intervene as soon as we hear his bloodcurdling screams, and he’s happy to get this negative attention because it’s better than no attention at all.

So it shouldn’t have come as such a shock when the principal of their school called. As I watched my wife’s reaction, I assumed the principal was recounting some terrible story about Robbie. As it turned out, she was calling about Zach. He had been goofing around on the bus on his way to school, and the driver told him to sit down and be quiet. Zachy, according to some eyewitnesses in the fifth grade, put his hands on his hips and told the bus driver, “You’re not the boss of me!”

The principal suggested that we have a little talk with Zachy, and so we did. We asked him about the incident, and, after squirming around for a few minutes, he finally came clean. “I was showing off,” he said. “But can I still have dessert?” And for some reason, my wife and I understood. We told him some halfhearted stuff about respecting your elders and then let him have his ice cream cone.

That night, Zachy and I had another one of our little talks.

“Daddy, what’s Robbie’s real name?” he asked, completely taking me by surprise.

“What do you mean?”

“What was his name before we adopted him?” he asked.

“It’s always been the same as it is now,” I told him.

Zachy seemed to understand. “It’s the same, but different,” he said.

This article was originally published in Family Life magazine and is reprinted with permission.