He was born to farmers in one of the poorest parts of Hunan Province in southern China. As a high school student, he built a small laboratory at home, believing he could be China’s Einstein, according to an article this week by Jiemian, a Chinese news website. He graduated from the University of Science and Technology of China with a physics degree.

But by the time he arrived in the United States on a Chinese government scholarship, Dr. He felt the golden age of physics was over, according to the article. He switched to biophysics and studied at Rice University in Houston, where he first worked with Crispr, the gene-editing technology he says he used to alter the babies’ genes.

After studying at Rice, Dr. He went on to postdoctoral research at Stanford University. In 2012, he returned to China, basing himself in the booming southern metropolis of Shenzhen, which gave him funding. Dr. He founded two genetic testing companies, Direct Genomics and Vienomics, which aimed to use gene sequencing for medical purposes.

Many scientists in China say the drive to succeed is so strong that they adopt a “do first, debate later” approach. Wang Yue, a professor at the institute of medical humanities of Peking University, said many scientists lacked awareness of medical ethics and of laws and regulations relevant to their fields.

“It is true that many scientists are very bold and think of science as their independent kingdom,” Dr. Wang said. “So they are not willing to listen to the outside world, including ethics committees and administrative agencies that want to supervise and review them.”

In China, clinical trials are vetted for ethical concerns just once, by a hospital’s ethics review committee. Dr. He said his research was approved by the ethics board of the hospital Shenzhen Harmonicare. The hospital denied that, although one of its shareholders had appeared in an Associated Press video talking about Dr. He’s project.