A study links having a male twin with women’s educational, financial, and childbearing decisions. Researchers suspect prenatal exposure to testosterone may play a role.

The extremely rare event, thought to be caused by two sperm cells fertilizing the same egg simultaneously, was last reported in 2007.

Now two years old, the Delaney twins were born joined at the head and were successfully separated in June 2017.

He Jiankui says he has successfully used CRISPR-Cas9 to tweak the genes of twins born earlier this month. Some independent experts are dubious.

A pair of calves was born about eight months ago in Tanzania’s Tarangire National Park.

A twin study suggests that the blood-sucking insects are more attracted to people with certain genes.

Twin study shows environmental factors play a greater role than genetic ones in shaping individual immunity.

Analyzing data from a large twin study, researchers have homed in on how host genetics can shape the gut microbiome.

More than school or family environment, a child’s genetics influences high school exam results.