There's an interesting "P.S." to the story of James Watson's early retirement after public outcry when he told a UK newspaper that he believed people of African ancestry were less intelligent - he has 16 times more genes of African origin than the average Caucasian.

The company deCODE Genetics performed the analysis using Watson's entire genome, which he released publicly this year.

"This level is what you would expect in someone who had a great-grandparent who was African," Kari Stefansson of deCODE Genetics told The Independent. "It was very surprising to get this result for Jim."

Stefansson visited the offices of Scientific American weeks ago to discuss the project.

In October, Watson stepped down as chancellor of Cold Spring Harbor Laboratory in New York after his remarks, which sparked strong public criticism.

Neither Stefansson nor a representative of deCODE Genetics responded to requests for comment and a copy of the analysis about Watson's genome.