GlobalP/iStock via Getty Images "Birds of a feather flock together," the old adage says, meaning that - for better or worse - people tend to hang out with those they find common ground with. You'll be hard-pressed to find a ballerina hanging out with a motorcycle gang, for example. Or a cool kid associating with a nerdy one. I'm not saying it can't happen, just that it isn't the norm. I'll acknowledge that opposites can attract. But in the case of humans, those opposites usually end up influencing each othe ...