Why do humans play chess in such a risk-averse manner?

Today I ask why computers playing among themselves have produced livelier games than recent matches of humans equipped with computer preparation.

That is from Kenneth Regan, much more at the link.  And here is part of his answer:

The reason may literally be that the computers have greater contempt for each other. The contempt factor is a term in a program’s evaluation function that makes it pretend to be a couple tenths of a pawn better off than it is, in situations where a drawing or drawish continuation is available.

The computers also have no awareness of high stakes that puts “staying in the game” ahead of maximizing one’s chance of winning.

The context of course, is the recent Anand-Gelfand world chess championship match, which featured unprecedented levels of computer preparation, and, arguably, a lot of very boring games of “theoretical interest” only.

So will iPhones make us all more boring?