The Science of Siblings is a new series exploring the ways our siblings can influence us, from our money and our mental health all the way down to our very molecules. We'll be sharing these stories ...

Dear Amy: My brother and I are the byproducts of extramarital affairs our mother had between 1943 and 1953, presumably to the same man. For decades we were led to believe that the father who raised us ...

Sibling dynamics play a profound role in shaping a child’s character. When brothers and sisters are expected to share household responsibilities, they gain more than practical skills, they develop ...