Twins FAQ: Quick Answers

Identical twins come from one fertilised egg that splits in two. Fraternal twins come from two eggs fertilised by two sperm, and share about half their DNA like ordinary siblings.

Fraternal twins can, mainly through the mother, because the tendency to release two eggs at once can be inherited. Identical twins happen by chance.

Almost never. Boy-girl twins are fraternal, except for extremely rare cases such as the semi-identical twins confirmed in 2019.

No. Fingerprints are shaped by tiny differences in the womb, so even identical twins have different prints.

Standard DNA tests cannot. Very deep sequencing can sometimes find the few small genetic changes that arise after the twins split.

Rates of fraternal twins are highest in parts of West and Central Africa. Igbo-Ora in Nigeria is often called the Twin Capital of the World.

Identical twins with reversed features, such as one being right-handed and the other left-handed. They are thought to come from a later split of the embryo.

Yes. Twins Days in Twinsburg, Ohio, held every August, is one of the largest gatherings of twins in the world.

The nine-banded armadillo, whose single fertilised egg normally splits into four identical pups.

It is almost the same size and mass as Earth, but its thick atmosphere makes its surface hot enough to melt lead.

No. Actual Twin is an independent educational brand from Fire Empire LLC. For medical questions about a twin pregnancy, talk to a doctor or midwife.