http://www.bloomberg.com/apps/news?pid=10000102&sid=a.eCGz4Nscks&refer=ukFrom the Bloomberg account, it looks as though the "functionally psychopathic" tendencies of the more successful subjects were probably less threateningly "psychopathic" than the more sensational headline implies.
Nevertheless, as the burgeoning field of Behavioral Finance is pointing out in so many ways, emotion does play a great role in trashing the returns of even the most supposedly rational long-term investors. There is evidence for this in tomes ranging from Jeremy Siegel's
Stocks for the Long Run (the bullish case) to Robert Shiller's
Irrational Exuberance (the bearish case).
Risk and return have been linked through history, hence the "equity risk premium," but the risk premium may have diminished substantially, hence a quandary for today's investor.
That the "psychopaths" who are less risk-averse should find higher returns by being able to resist emotional swings so is no surprise. It confirms what has been known for decades (though it may have less valence as we move through economic time): that a willingness to buy and hold "higher risk" assets (a basket of stocks vs. a bunch of bonds) over a period of time, will generally give an investor a higher rate of return (though there is evidence that this formula for success is diminishing in its power).
Successful investing over the long-term has long involved suppressing emotion (such as the emotions so many investors felt and acted on when during the 1990s bull market: to buy high-priced holdings when chasing "hot stocks" on the upswing, and to sell those same plummeting holding holdings at the bottom of the market; the exact opposite of "buy low/sell high."). This is why folks who can afford it often hire money managers who can allegedly suppress such emotions. But of course they often end up hiring brokers who bilk the fuck out of them for commissions on shitty trades.
And this is why adopting and abiding by a sound asset allocation strategy is the key to 94% of investment success (I'm not making the number up - there have been studies).
Anyway, oh, blah blah blah.
Behavioral Finance is an interesting field of study. But I don't think the "psychopaths make the best investors" is a fair representation of what this studay is actually discussing.