Folks who use two hands are, in general, more concerned about safety, accuracy, sureness of grip, and by extension, rules, responsibility, reliability. In short, a bit square. For instance, a driver who takes seriously the social responsibility of steering a large, potentially deadly vehicle, will keep two hands on the wheel in the approved "10 o'clock and 2 o'clock" position. If she has to remove one hand, she will probably move it to the 12 o'clock position to prevent her car weaving across the lane while she adjusts the reception of her classical music station. A one-hander, by contrast, might steer with one hand on the bottom of the wheel, the other dangling outside the window, and the subwoofer pounding away in the back.

Two-handers will use one hand for a task only if they have a high degree of confidence in their skill at that task, whether it is driving, bowling, typing, holding a baby, lifting a heavy bag, or performing any other physical function.

Americans, when eating, will normally put down their knife after cutting their food and switch their fork to their preferred hand. Canadians are taught to keep their knife in their right hand, and their fork in their left hand, and thus force themselves to become proficient at eating with what is, for most people, their less dextrous hand. That distinction speaks volumes about the personalities of two countries.

One-handers are people who figure that the universe has some slack in it, and there's no reason not to take advantage of that. If they carry a laden plate while reading, if they smoke while driving, if they use their cell phone in the washroom, nobody will really mind, right? And if things do go wrong -- they spill food, smash their car, miss the urinal -- there's always somebody who'll clean up, right? Yes, and that person is a two-hander.