"As advisors, of course, we see our role in overcoming the irrational, emotional, inaccurate elements on behalf of our clients," said Davies. "But the implications of this for the mass markets are much greater."
Markowitz said the argument that intelligence and personality sometimes trump rationality in guiding investors has little bearing on his work. His theory comes down to the view that anyone hoping to get the highest payout at the lowest risk should broaden their asset ownership.
"It's advice for the individual investor," Markowitz, 84, said in a telephone interview. "I am delighted to learn the more intelligent a person is, the more likely they are to act in the spirit of what I wrote."