Three women were brought to the Singapore General Hospital, each in the same condition and needing a blood transfusion. The first, a Southeast Asian was given the transfusion but died a few hours later. The second, a South Asian was also given a transfusion but died a few days later. The third, an East Asian, was given a transfusion and survived. That is the X factor in development.

1967, cited in Lee Kuan Yew: race, culture and genes, Michael Barr in Journal of Contemporary Asia (01/1999)