© Felix Mizioznikov |ShutterstockSome countries, such as Benin in central Africa, have high twinning rates compared with places such as Asia, new research is showing.
When it comes to having twins, not all regions are created equal. Central Africa snags the record for the highest twin birthrate, while Asia and Latin America have much lower rates of twinning, according to a new international study and global twins database.
The central African country of Benin has the highest national average of twinning, with a whopping 27.9 twins per 1,000 births, the researchers added.
The findings may help answer questions about the causes of twinning, which may range from a mother's age, height and diet to genetic factors that are passed down through the maternal line, as well as mortality differences between boys and girls in certain regions.
Tallying twinsTwins have long fascinated the world, even making their way into myth and religion, from Castor and Pollux, the brothers from
Greek mythology and basis for the constellation Gemini, to the epic tales of the Hero Twins in the sacred ancient Mayan book known as "Popol Vuh." Identical twins have proven vital in science as well, in particular with questions about nature and nurture - since they are genetically identical, any differences seen between them can reveal the effects that environment might have on individuals.
Until now, scientists had a very incomplete picture of the number of twins around the world. Reliable national information on twinning was only available from highly developed countries with good birth registrations. Data from less developed regions were often weak or lacking all together.