Harris was born on October 20, 1964, in Oakland, California.Her mother, Shyamala Gopalan, a biologist whose work on the progesterone receptor gene stimulated advances in breast cancer research, had arrived in the U.S. from Tamil Nadu in India in 1958 as a 19-year-old graduate student in nutrition and endocrinology at the University of California, Berkeley; Gopalan received her PhD in 1964.