The psychological trick that gave the Vikings an edge in battle: NatGeo: Viking armies were organized into boat crews comprised of several dozen men from the same area. In between battles, the men lived together at sea for weeks at a time. “You row, pee, eat, drink, and fight together,” Viking expert Igor Gorewicz told National Geographic. “There’s a very close connection with people from the ship, and morale is very, very high.” via @sunjayjk