If you're like me, you check your Facebook feed for the daily notification of all your friends' birthdays, then shoot them a quick greeting (with or without appropriate emojis and GIFs). There are some days when I'm amazed at how many people share the same birthday, and sometimes weeks pass without a prompt. It makes me wonder (and maybe you do, too): What is the least popular birthday of the year? Who are the folks who can brag of having the fewest b-day twinsies?
Taking data from sources such as the Centers for Disease Control and the Social Security Administration, The Viz writer Matt Stiles created a "heatmap" chart of birthdays (the most popular birthdates are a dark purple; the least popular are a light pink), as well as a ranking list from 1 to 366. At the very bottom of the list: December 25.
That's right: The day when people are least likely to be born is also the day when millions of other folks get presents. Talk about irony!
What's even more interesting is that the runners-up for least popular birthdays also fall into the major-holiday category. According to that same chart, #364 on the list is New Year's Day, January 1, followed closely by Christmas Eve (December 24) and July 4. It seems we really like to keep our birthdays and holidays separate, doesn't it?
On the other end of the spectrum, September leads the pack in popularity; nine out of the top 10 most common birth dates occur within that month. (September 9 holds the #1 spot, for the record; do you know anyone with that birthday?) August and July dates come close to the top as well, with a few late-December days scattered in there for good measure.
What accounts for the lack of a holiday baby boom? It could very well be connected to the conception date. A report published in the journal Demography suggested that there's a link between seasonal temperature and fertility, with fewer babies conceived during warm-weather months. Another set of researchers theorized in Epidemiology that sperm quality may be lower in the summertime, making conception less likely. True, Christmas babies are conceived in early April, but in the southern U.S., even springtime can get mighty warm. Not to mention the part libido plays; it's hard to get in the mood when it's too darn hot.
Parents expecting in late December may also be opting to schedule C-sections for days other than the 24th and 25th because of the stigma of being a Christmas baby. Holiday-born children told The Globe and Mail melancholy stories of combined Christmas/birthday gifts, Yule log birthday cakes, and feeling less special than siblings with spring and summer birthdays. In Greece, it's even considered super-unlucky to be born on Christmas; superstition has it that December 25 babies may turn into mischief-making holiday goblins called Kallikantzaroi.
Moms are also least likely to schedule cesareans for February 29 during leap years, according to FiveThirtyEight, in order to spare their children the disappointment of having an exact birthday only once every four years. Indeed, per Stiles' heatmap, leap day birthdays rank a low #347.
If you take a look at the baby-boom days, a very different pattern emerges. A baby born on the most-common day of September 9 would be conceived around December 17, and the second-most popular birthday, September 19, would mean a conception date of December 27. And so on through the list. It seems that though we prefer not to have Christmas babies, we sure don't mind getting busy making them when the holidays come along.
No matter when your friends' birthdays fall, give them a social media shout-out, because we all deserve to feel special at least one day a year. But if you have a Christmas or New Year's Day birthday bud, try to show them a little extra love — and remind them that, unlike all those September kids, they're members of a very exclusive club.
After experiencing a traumatic c-section, this mother sought out a doula to support her through her second child’s delivery. Watch as that doula helps this mom reclaim the birth she felt robbed of with her first child, in Episode Three of Romper's Doula Diaries, Season Two, below. Visit Bustle Digital Group's YouTube page for more episodes, launching Mondays in December.