Interesting Stuff About Twins
Miri is the middle child between two sets of twins. Two sets of twins? Is that even possible?
Sure it’s possible. In fact, the second set of twins is statistically more likely than the first set because some women have a genetic disposition to produce twins. But how many people, after having one set of twins, go on to have another set? That’s the real question. That’s the tough question. That’s the question I’ve been trying to answer for about four years.
In the first edition of The Magic Half, Miri’s father says that hers is a one-in-eight-million family because they have two sets of twins. I manufactured that figure from some statistics I found on a website called “Facts about Multiples” and it is totally incorrect. I am no statistician. If you want to know the truth, I almost flunked out of college because of a statistics class. But luckily, I have a friend who is statistically BRILLIANT, and he has a whole slew of friends who are even more statistically BRILLIANT, and it drove all of them berserk to think that I had published a figure that was incorrect, so they set to work. Here’s what they said: the likelihood of having twins hovers around 1 in 80 worldwide (fairly unusual in Asia, quite common in Africa), but the likelihood that a family that has one set of twins will go on to have more children is wildly variable, about 1 in 4 in poor countries, about 1 in 12 in more developed countries. After a lot of fussing, the statisticians agreed that it was “reasonable” to split the difference and calculate the odds of having two sets of twins in one family by using 1/80 x 1/80 x 1/8, which equals 1 in 50,000. In other words, vastly more likely than 1 in 8 million. Newer editions of The Magic Half contain this much less extravagant figure. It doesn’t sound as good, but it’s closer to the truth.
The odds of having three sets of twins are, by contrast, shockingly tiny. You take 1/80 x 1/80 x 1/80 x 1/8 x 1/10 (the last figure is the likelihood that a family having two sets of twins will go on to have another kid), which equals 1 in 49 million. Hardly anyone has three sets of twins, but good luck to them if they do.
I herewith apologize for being such a dork about math, but looking on the bright side, those of you who bought the edition with the incorrect figure may wind up with an extremely rare and valuable book that you can sell for millions of dollars. That’s my kind of math.
Some real, true statistics about twins:
Fraternal Twin Rates
Worldwide: 1 in 43
Japan: 1 in 150
Nigeria: 1 in 22 (True! But why?)
Identical Twin Rates
Worldwide: 1 in 280
(Get this: In the United States, one-third of all twins born are identical; in Japan, two-thirds of the twins are identical.)
Cojoined Twin Rates
Worldwide: 1 in 50,000
Imagine having more than one set:
A woman who is known to history only as Mrs. Fyodor Vassiliev (which is totally unfair) had not one, not two, not three, not . . . Okay—she had SIXTEEN sets of twins, also four sets of quadruplets and seven sets of triplets. Altogether, the poor lady had 69 children, and then she died and Mr. Fyodor Vassiliev remarried and had 18 more children, including some more twins. Catherine the Great, Empress of Russia, found this little population explosion charming and rewarded—guess who? Fyodor!
Some unnamed woman in Italy had ELEVEN sets of twins in eleven years, between 1936 and 1947. Pretty crummy time to have twenty-two new mouths to feed.
There are 141 recorded instances of three sets of twins birthed by the same mother.
There have been 49 instances of septuplets in history. On November 19, 1997, the McCaughey family of Iowa produced the first set in which all of the babies (and the mother) survived.
If identical twins marry identical twins, their children will legally be first cousins, but genetically, they’ll be siblings.
The earliest written record of cojoined twins were the Biddenden Maids, Eliza and Mary Chulkhurst, born in 1100 in England. When Eliza died at the age of 34, it was suggested to Mary that she might survive if separated from her sister. She refused, saying, “As we came together, we will also leave together,” and died six hours later.