In the state of Rio Grande do Sul, Brazil, just off the Argentine border, is a small town called Cândido Godói. With a population of roughly 7,000, Cândido Godói is a modest farming community, much the same as its neighboring municipalities. However, there is one significant, weird distinction about this sleepy Brazilian town: it has a staggering amount of twins.
The rate of twin births is around 10% in Cândido Godói, which is nearly 10 times higher than the average in Rio Grande do Sul. It's a strange phenomenon and has puzzled experts from around the world. Throw in the fact that sadistic, twin-obsessed SS doctor Josef Mengele passed through the area and that many of the residents have blonde hair and blue eyes, and you'll get a mystery that's eerily more intriguing.
So what's the explanation for a small farming village seeing an abundance of twins? Something in the water? A unique diet? Human experimentation? Let's explore the most prevalent theories about the unusual birth stats of Cândido Godói.
Dr. Josef Mengele was an SS Captain and doctor who was obsessed with eugenics. At Auschwitz, he performed gruesome experiments on prisoners, many of whom were children, as a part of his research on creating a master race. Mengele - who is sometimes referred to as the "Angel of Death" - became enamored with fraternal twins, seeing them as ideal human test and control subjects. The macabre doctor carried out a broad range of offenses, many of which amounted to ending the lives of his "patients." When the Third Reich fell, he fled to South America to avoid prosecution.
Jorge Camarasa, an Argentine historian, speculates that Mengele passed through Cândido Godói at one point as he roamed Brazil in the 1960s. Locals at that time claimed an urban German doctor took an interest in the pregnant women of the village, leading to a boom in twin births. Could this be the cause of Cândido Godói's strange surge in doubles? Not likely.
While artificial insemination - when combined with fertility drugs - can increase the odds of multiples, it doesn't cause them on its own. And, at the time, artificial insemination was strictly theoretical - it had never been successfully performed in humans. Unless Mengele had a revolutionary procedure and a type of hybrid sperm on his hands that the world remains clueless about, this explanation is probably false.
Anencia Flores da Silva, a former mayor of Cândido Godói, attempted to research the twin mystery and kept coming across the name Rudolph Weiss. Weiss was a German medic who was reported to have treated various local women for varicose veins, offering them strange potions and often taking blood.
Many in the village now accept that "Dr. Weiss" was likely the exiled SS doctor Josef Mengele.
While the idea of a village of twins being created by Third Reich masterminds is certainly an intriguing one, Cândido Godói's elevated twinning rate could actually be due to a taboo human practice that has had genetic consequences for centuries: inbreeding.
Brazilian geneticist Ursula Matte concluded in a 2009 study that the town had experienced an unusual volume of inbreeding. The practice of mating between closely related people can carry on genetic traits that increase the chance of twins. Matte even isolated a gene that increased the chances of twin birth in the women of the town. Many argue that this theory - combined with some other factors - is the most plausible explanation for Cândido Godói's high number of twins.
In her research, Matte also poked a hole in the idea that Josef Mengele orchestrated any kind of twinning wizardry. Baptism records in the village going back as far as the 1930s - decades before the doctor's arrival - show an unusual amount of twins being born.
Believe it or not, Cândido Godói is not the only town in the world with a disproportionate number of twins. In the Nigerian village of Igbo-Ora, about 50 sets of twins are born per 1,000 live births, making roughly 10% of their population fraternal or identical twins. Research into the village has indicated that this staggering number of multiples could be due to the diets of the mothers, specifically related to a type of yam. Studies have shown that high consumption of the vegetable may release a chemical that stimulates the ovaries to release an egg from each side, in turn leading to twins.
Could something similar be happening in Cândido Godói? Maybe, but it wouldn't be the sole factor. Scientists speculate that even in Igbo-Ora, genetics play a much more significant role in the twinning rate.