This may be partially "futile". Though my experience (from teaching and 15y of recruiting) is inconclusive I still lean strongly towards the "double hump" theory is true.

"All teachers of programming find that their results display a 'double hump'. It is as if there are two populations: those who can, and those who cannot, each with its own independent bell curve."

http://www.eis.mdx.ac.uk/research/PhDArea/saeed/

http://www.codinghorror.com/blog/2006/07/separating-programm...