Twins occur in about one out of 90 human pregnancies in the US. As a rule, at conception, one sperm fertilizes a single egg to produce a zygote. Two thirds of twins are fraternal, with fertilization ...

Twins may often make you imagine two babies with the exact physical features, such as eyes, smile, and even voice. However, this is not the case with every twin, as some look totally different from ...

Fascination with twins and what twin studies tell us about human nature is universal. There is no question that behavioral and medical science advances have happened largely because twins yield a ...

The special relationship between twins allows researchers to examine the differences between genetic and environmental influences over both physical and mental health, as well as traits and behaviors.

In 2004, Michigan police found that DNA recovered from a crime scene matched that of Jerome Cooper, a notorious criminal. But what seemed like an open-and-shut case got complicated when the cops found ...

I never believed in love at first sight until I met my now-husband. I couldn't recognize him from his identical twin brother over the phone. We ended up having fraternal twins, and I got to experience ...

A new analysis of studies spanning the last century finds that differences in schooling appear to explain a large portion of the IQ gap between identical twins who were raised in separate homes. The ...

Jedidiah Duggar and Katelyn Nakatsu were the first Duggar couple to welcome twins. They announced their big news and held a gender reveal for both babies. Welcoming two little girls was something Jed ...