For the best experience, please enable JavaScript in your browser settings. Following the Kakamega twin puzzle that has drawn the attention of the entire country, we ...

Around 1 in 250 pregnancies result in identical or “monozygotic” twins, but the mechanism behind monozygotic twinning has remained elusive, partly because the phenomenon is so rare and partly due to ...

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 ...

When you’ve just had identical twins, it’s normal to spend a lot of time looking down at their squishy little bodies and analyzing every subtle way they differ from one another. Unlike fraternal twins ...

For more than a century, scientists have debated whether intelligence is mostly a product of nature or nurture. Identical ...

There’s a common assumption that intelligence is largely determined by genetics. After all, previously published studies ...

Sam and John Fetters are identical twins with autism. But Sam is in college, while John still struggles to form sentences. Their experience may... These identical twins both grew up with autism, but ...

You've probably heard of identical and fraternal twins, but a report published Thursday says there's a third kind -- sesquizygous twins or "semi-identical." Identical -- or monozygotic -- twins pop up ...