Donald was my PhD advisor in Boston. I have forgotten all of what he had taught me about evolution and molecular biology, but I do remember clearly what he told me once at his house party, back in 1994.

His family had just moved into a beautiful colonial house in Cambridge and invited everyone working in his lab over for a party. While all the adults chatted over free flowing white wine, his preschool twin girls chased each other around, scattering pearls of laughter in every room.

"They are so cute," I said to Donald. "Which one is smarter?"

Donald immediately pulled me aside and whispered: "We shouldn't say anything putting either down. They are both great in their own ways."

I remember being very embarrassed by my cultural faux pas. To us Chinese, to be put down, by parents and peers, is a natural part of growing up. In high school, my grades were never good enough for my parents. When I was number two in my class, they pointed to number one. When I reached number one, they pointed to some genius who had just won the Maths Olympiad.

But Americans tend to believe in the power of encouragement and positive outlook on one's life. Thus one often hears enthusiastic "super", "awesome", "fantastic" and "good job!" To us Chinese, how could that kind of seemingly superficial praise really encourage hard work and achievement?

Donald seemed the antithesis of that Chinese prejudice. In his teenage years, he dropped out of school and worked in hospital, construction and boat building. Then he went to a community college to get an associate degree. It was there, at the age of 23, that he discovered his passion for science. He studied hard, received top grades and transferred to Berkeley. After finishing his bachelor's degree, he studied at Harvard for his PhD and later did post-doc work at the prestigious Mass General Hospital.