I don't doubt his message about widespread incompetence, but for someone lecturing on incompetence, he should probably be more careful about what he actually knows, and what he only thinks he knows .

http://www.videosift.com/video/Richard-Feynman-on-Social-Sciences

I think successful males trend toward choosing tall, pretty females, so those genes tend to get sorted together... they call it assortive mating.

And maybe people who are very tall get constant positive feedback from society.. regarding them as having good leadership skills... so they're encouraged to go into leadership, and society gives them more leeway. That kind of bias could genuinely increase their leadership skills.

If this speaker's theory was correct, though, the prediction would be that height among leaders would inversely correlate with job performance and IQ (because they're being selected for their positions partially because of an arbitrary measure). I doubt that prediction would pan out.

here is another video on similar topic. it talked about the lake wobegon effect and the dunning kruger effect

http://www.youtube.com/watch?v=Jb8CXDhLPsA