I think he means to say he's one of the people who believe differences in measured iq scores between ethnic groups reflect underlying genetic potential for intelligence.

Some different perspectives on the issue:

http://andrewsullivan.thedailybeast.com/2011/11/the-study-of...

https://www.theamericanconservative.com/dreher/2011/11/29/th...

http://www.dailykos.com/story/2011/11/29/1040695/-Andrew-Sul...