In some ways, she is a typical teenager: Gracelyn Shi likes putting on make-up, going shopping and meeting her friends. However, the 16-year-old from Toronto spends the rest of her time in front of the computer, where she does bioinformatics research, programmes in Python and makes YouTube videos in which she explains how artificial intelligence is revolutionising medicine. “When I was eight years old, I was already interested in stem cells,” she says. And no, she says she is not smarter than her classmates, merely more curious. That’s hard to believe, considering the speed with which Gracelyn talks about genetics and machine learning. She spent last summer interning at a Canadian bank helping them build machine-learning applications. “Machines are so much faster than we are, especially when it comes to recognising patterns,” says the young woman, and describes the results of a study in which computers evaluated tumour images more accurately than doctors with years of experience. AI also plays a major role in deciphering our genetic code. However, as she points out, “When the algorithm identifies a defect in the DNA, it doesn’t ask itself whether correcting the defect would cause another problem.” Humans are therefore needed to place information in a larger context and evaluate situations from an ethical viewpoint. This is another reason why she aims to learn more every day: to understand the limits of artificial intelligence.