“Which Twin is Older?” Does It Matter?

  • By: Sandra
  • Date: March 18, 2022
  • Time to read: 8 min.

Last week, I was reading with great interest about a couple who have decided to keep the sex of their baby a secret so that he/she can choose his/her own gender when he/she gets older.

“Do you know if it’s a boy or a girl?” is definitely the most asked question of all pregnant women but if those moms give birth to twins, there’s a shift in interest and then for some reason the question suddenly becomes, “Which twin is older?”

Which Twin Born First

The Canadian couple say they’re withholding the sex of their child to free him/her from the constraints of gender social norms. Parents of twins who withhold their multiples’ birth order say they do it to prevent sibling rivalry. They don’t want their twins to fall into the traditional birth order hierarchy with “Twin A” becoming the more dominant partner. And while the Canadian couple’s experiment has far, far greater social implications (some may say even dangerous), I can’t help but draw a slight comparison. Both goals are idealistic but do either accomplish what they set out to do?

From a purely practical point of view, keeping twins’ birth order under wraps is difficult! It’s never easy to keep a secret. First, you have to decide who to tell and who not to tell. Then there are the birth certificates to keep hidden from inquisitive children. And what happens when they need to apply for a passport or driver’s license?

They Are the Same Age

I’ve never been one for keeping secrets (maybe because my Italian-American family thrived on them). They’re way too much work. When something’s a secret, it takes on an energy all its own, and it usually ends up possessing more power than it deserves. Parents who hide their twins’ birth order may also unintentionally give off the vibe that their children can’t handle the truth so therefore they need to keep it a secret. That may in turn fan the flames of curiosity even more than if they had told their twins outright. Furthermore, on some level, parents in both these instances are denying their children of who they really are. After all, if you’re a boy, you’re a boy; if you’re five minutes older, you’re five minutes older. So what?

Baby boy or baby girl? First born twin or second? Some would ask, does it really matter? What’s wrong with being either? Isn’t there beauty in all those roles? Instead of trying to keep these secrets, wouldn’t time and energy be better spent putting ideals into action? After all, when it comes to raising kids, it’s not what you say (or don’t say) but what you do that matters more.

For instance, the Murray triplets have no idea who was born first. It’s always been the “Big Neighborhood Mystery” around here, yet Bobby has his own bedroom while little Samuel and John share a room.


Bobby may or may not be the oldest triplet but his parents are sure treating him as such, according to his cotriplets. Talk about their mother and father setting up a sibling rivalry!

Which Twin Born First?

I admit the question, “Which twin is older?” is an annoying one, right up there with, “Who’s smarter?” but my twins’ birth order has always been part of our family fabric. Although I truly understand the intent of parents who choose to keep it a secret and respect that, I also believe that if you really want to diminish the importance of birth order and put the brakes on twin rivalry, these tips are more important.

  • Never put one twin “in charge” of the other, and always make each child responsible for himself. If money needs to go to school for a class trip, for instance, give each twin his own even if they share a classroom, the younger brother does not need to be going to his older by a few minutes sibling for anything!
  • When it’s time for cell phones and house keys, don’t make them share. Buy double. And never, never have one twin check up on the other when you’re not home. If you want to know if one did his homework, just ask him when you return.
  • Don’t try to squash twin rivalry. According to experts, some form of sibling rivalry is not only natural but good. And if you try to put a stop to it, it will just go under the radar where it will fester and eventually blow up. Instead allow your identical twins to work out their own issues but set some boundaries. (“I know that you’re upset that Sue made the swim team and you didn’t, but you may not hide her favorite swim suit.”)
  • Play down the importance of birth order. When someone asks you, “Who’s older?” Smile, laugh and then answer with something like, “Gee, let me think about that for a moment it’s been so long ago, they are identical twins and the same age so I just don’t know.” And then change the subject.
  • Mix it up. From singing “Happy Birthday” to them or signing holiday cards to choosing the weekend movie or having a turn on the computer, give each child the opportunity to go first.
  • Follow No-Brainer rules. Don’t refer to your twins as the “younger” or “older” to family and friends, and when you introduce them to someone new, never go by birth order.

Should I Tell My Twins Who is Older?

“Should I tell my twins which identical twin was born first?”

If you had asked me this question 17 years ago when I was pregnant with my fraternal twin boys (check our guide on what to expect with twin pregnancy), I would have looked at you like you had two heads. Of course, you should tell them. And true to my word, we never shied away from disclosing to our boys who was older even if only by mere minutes. What’s the big deal, right, its hardly an age difference? 

But lately, I’ve been reconsidering my position, and now I’m not so sure and I wonder if their personalities would have been different if we hadn’t told them.

So what gives? What would make me reconsider? If the twins switch positions would it make a difference?

Younger Brother is More Carefree

My doubt is due in part to a recent conversation I had with my sons where I asked them what it’s been like growing up as a twin. Although there are very few secrets in my house as my kids have always freely expressed their opinions and emotions, it surprised me (shocked, really) when my “younger” twin told me that he feels indeed like the younger of the pair.

Furthermore, his elder brother twin confirmed that he often feels like he’s the big brother since his second born twin brother doesn’t always make good decisions.

When the second twin would suggest a questionable or dangerous adventure, for instance, the older twin would then enlighten his younger cotwin on the flaws in his plan and suggest another more productive (and thankfully safer) alternative—the stereotypical carefree younger sibling taking direction from the older, wiser sibling. 

So how did this happen? Did I set this paradigm in motion by casting them into these roles when I told them who was older or was it inevitable, instead evolving slowly and organically based on their innate personalities? (In my defense, my “older” twin has always been a bit more serious than his cotwin from the day he was born—cross my heart.) Hard to tell and obviously too late now. Furthermore, does it really matter? Would two offspring who were not twins act the same?

Annoying Twin Questions, Are they identical twins, who’s older…

The question “who’s older?” ranks right up there with the ubiquitous “are they fraternal or identical?” As parents of twins, we hear these questions constantly during the first few years from neighbors, coworkers and even strangers as we push that double stroller through the mall. But once our twins hit the school years, we no longer field those questions on a daily basis.

Instead, our twins themselves take them on. Classmates, teachers, coaches—they all want to know and they all ask. And if you watch any twin, you can see how adept they become at answering. My own kids had a five-second shtick that went something like this:

Stranger: “Who’s older?”

Older Brother: “I am!”

His brother Ronan: “Yes, but I’m taller!”

This short bit would undoubtedly send the stranger into fits of laughter, my twins satisfied in contributing to their amusement.

But if my twins didn’t know their birth order and said so when asked, would the questions have stopped or just changed direction: “What do you mean you don’t know who’s older?”  or “Did you ever try to find your birth certificates to look?” (which one is baby a or baby b) or even, “Who do you think is older?” (I’m sure they would have come up with another entertaining gag to satisfy their adoring public and they’re annoying baby riddle questions..)

Some say that when twins know who was born first, it sets up a rivalry between the pair. I’m not so sure about that. There are plenty of things that twins compete about—from grades and sports to parental attention and friends—I’m not sure birth order and being the second baby is one of them.

Instead I worry more that I’ve somehow restricted a part of each them by simply making one older. Does the younger one let go of his responsibilities because he is the younger? Does the officially older one feel a duty of care?

Vaginal Births vs C Section

When you give birth to twins with a vaginal delivery, there can be a big time difference in their birth times compared to twins born via c section. The longest confirmed time between twin births is 90 days, according to Guinness World Records. Molly and Benjamin West, fraternal twins, were born in Baltimore on January 1 and March 30, 1996. Having a twin vaginally can also increase the risk of one or both twins being breech.

When you give birth to twins via c section, they are more likely to be born at the same time. This is because the surgery induces labor and delivery. The downside to this is that there is an increased risk for complications like infection and blood clots.

Take Away

So, does it matter who is older? For the most part, I think the answer is no. But as parents of twins, we can’t help but wonder if there are any ramifications to one twin being older than the other. =>Do they compete more for grades or for our attention? Are there any psychological effects to knowing who was born first? Only time will tell. In the meantime, my advice is to not worry about it and let your twins be whoever they want to be—and answer all those pesky age difference and other twin questions themselves.