Humans are fundamentally social animals. Our social nature means that we interact with each other in positive, friendly ways, and it also means we know how to manipulate others in a very negative way.
Neurophysiologist Katherine Rankin at the University of California, San Francisco, has also recently discovered that sarcasm, which is both positively funny and negatively nasty, plays an important part in human social interaction.
So what?
I mean really, who cares? Oh for God's sake. Don't you have anything better to do that read this column?
According to Dr. Rankin, if you didn't get the sarcastic tone of the previous sentences you must have some damage to your parahippocampal gyrus which is located in the right brain. People with dementia, or head injuries in that area, often lose the ability to pick up on sarcasm, and so they don't respond in a socially appropriate ways.
Presumably, this is a pathology, which in turn suggests that sarcasm is part of human nature and probably an evolutionarily good thing.
How might something so, well, sarcastic as sarcasm, be part of the human social toolbox?
Evolutionary biologists claim that sociality is what has made humans such a successful species. We are masters at what anthropologists and others call "social intelligence." We recognize and keep track of hundreds of relationships, and we easily distinguish between enemies and friends.
More important, we run our lives by social calculation. A favor is mentally recorded and paid back, sometimes many years later. Likewise, insults are marked down on the mental score card in indelible ink. And we are constantly bickering and making up, even with people we love.
Sarcasm, then, is a verbal hammer that connects people in both a negative and positive way. We know that sense of humor is important to relationships; if someone doesn't get your jokes, they aren't likely to be your friend (or at least that's my bottom line about friendship). Sarcasm is simply humor's dark side, and it would be just as disconcerting if a friend didn't get your snide remarks.