A Village with an Unusual Pattern
In southern Brazil, near the Argentine border, lies a small municipality that has puzzled scientists for decades. Cândido Godói, with just over 6,000 inhabitants, is no ordinary town. It has become famous worldwide for its extraordinary number of twin births, a phenomenon most concentrated in a settlement called Linha São Pedro.
A Strikingly High Twinning Rate
While the average twinning rate in the state of Rio Grande do Sul is 1.8%, Cândido Godói’s is around 10%. This figure surpasses even the highest known national average, such as southwestern Nigeria’s rate of 4.5 to 5%. Studies revealed that nearly half of the town’s twins are identical, exceeding the global average of 30%.
The unusual pattern has been recorded since the early 20th century, when immigrants first arrived in the area, including several families with twin births. Over generations, the trend persisted, marking the community as exceptional.
Searching for Explanations
Most residents are of German or Polish ancestry, with many tracing roots to the Hunsrück region of Germany, an area also known for higher twin birth rates.
One explanation is the genetic founder effect: rare genetic traits carried by the small group of settlers became more common in their descendants due to isolation and intermarriage. This theory has received support from geneticists who argue that historical records confirm twin births long before outside speculation began.
The Mengele Theory
Controversy arose when Argentine historian Jorge Camarasa suggested another possibility. Josef Mengele, the Nazi doctor notorious for experiments on twins in Auschwitz, fled to South America after World War II. He reportedly lived in southern Brazil in the 1960s, and Camarasa claimed his presence might have influenced the rise in twin births.
According to this idea, Mengele conducted secret experiments on local women. However, historians and scientists widely dispute this theory. Local historian Paulo Sauthier noted that Mengele did not engage in twin studies while in Brazil, and genetic data show that Cândido Godói’s high twin rate predates his arrival.
Not Alone in the World
Cândido Godói is not the only place with a remarkable concentration of twins. Similar patterns are seen in Igbo-Ora, Nigeria, often called “Twin Capital of the World,” and in Kodinhi, India. Yet Cândido Godói’s consistency and long history continue to attract researchers who see the town as a living case study in population genetics.
In southern Brazil near the Argentine border, Candido Godoi became known for an unusually high number of twin births, most centered in the Linha Sao Pedro settlement.
The town has about 6,151 residents, and its photos and records drew scientists worldwide…🧵👇 pic.twitter.com/3lhMYNbV92
— Fascinating True Stories (@FascinatingTrue) October 1, 2025