Although there are some rare exceptions, identical twins are almost always the same sex. Because identical twins occur when a single fertilized egg splits and forms two embryos, each embryo has the ...

Identical, or monozygotic, twins develop from the same fertilized egg that splits into two. These twins are the same sex and share the same genes. Sometimes called paternal twins, identical twins ...

These folks are giving a new meaning to the term "twin flame." The couples first met at the Twins Day Festival in Ohio, and according to the sisters, they knew it was love within 15 minutes of ...

From Romulus and Remus—the myth of the twin brothers who founded the city of Rome—to the synchronized speech of Australia's "Twinnies" Paula and Brigette Powers, identical siblings have long inspired ...