Remember the Seinfeld episode featuring the "close-talker," an overly pleasant fellow named Aaron (played by Judge Reinhold) who stands just a little too close to people when he's talking to them? If you thought someone must have had brain damage to be so nice, perhaps you weren't far off: a new study out of Caltech associates close-talking with damage to a specific region of the brain.
The amygdala, to be exact. A pair of almond-shaped brain regions, the amygdala is known to be a hotspot for feelings like anger and fear. Thus, a person with a damaged amygdala tends to be less misanthropic than the rest of us, sometimes bordering on complete naivety.
The Caltech scientists happened to know a woman with a clear lesion on her amygdala, which presented an intriguing scientific opportunity: if you find someone with damage to one particular area of the brain, it can help to show you what that region does. This patient, whose name remains anonymous and goes by SM in the study, shows some of the clear signs of amygdala damage: she's overly friendly and trusting, and has a difficult time picking up on indicators of fear or aggression on another person's face.
But in their new experiment, the Caltech scientists found something else: she doesn't understand personal space. The researchers set up an experiment with her and 20 volunteers without amygdala damage, and asked each participant to walk toward a researcher and stop wherever they felt comfortable. The 20 volunteers, over multiple trials, averaged stopping about two feet away, but SM would stop only one foot away, and never seemed to be uncomfortable at any distance or lack thereof
These results are still early; it's hard to work up a statistically significant data set when you need to find someone with a very particular form of brain damage to do a study. And the preferred amount of personal space varies from culture to culture.
However much personal space one requires, the upshot is clear: if the same area of our brains that lights up for anger and fear is also connected to proximity to other human beings, be careful about violating somebody else's space.