Though it may be an individual sport, parkour is neither a solitary activity nor a zero-sum game.

FORBES: Parkour and Entrepreneurs

According to a new study by the Centres for Disease Control and Prevention (CDC), which looked at five cities with high numbers of gang murders between the years 2003 and 2008, drug trading or usage and other criminal activity ranged from zero to 25% of all gang-related killings.

ECONOMIST: Gang violence

When researchers zero in on electrical activity in yet another area, they can tell which parts of commercial messages, if any, are encoded in the experimental subjects' long-term memories.

FORBES: In Search of the Buy Button