Missed this on History Channel last night but discovered that part 4 to 7 is available on YouTube. I think there is more than enough evidence here to cause you to doubt Lee Kuan Yew obstinate views about genes, race (this two are related) contribution to intelligence. What is intelligence anyway? Truth is we don't really know. We have captured some of it which we believe is useful but there is more.
Insert: Can't find Part 1 to 3 on YouTube, but Daily Motion has it. See http://www.dailymotion.com/video/xb9i7a_race-and-intelligence-1-7_school