Though the genes in question have yet to be identified, this result suggests they are too abundant to be there by chance in other words they are being kept in the population by natural selection because psychopathic behaviour confers a selective advantage.

ECONOMIST: Evidence that psychopaths are born, not made

If you are sloppy with selection or execution you will fritter away the ETF cost advantage.

FORBES: Magazine Article

Or just swing in for a cup of coffee and take advantage of its sprawling, outdoor seating and ample board game selection to pass the night away.

BBC: A vegetarian in Texas