Personal space has a measurable boundary
People have a sharp no-fly zone around their faces. Though its boundaries depend on the person, this discomfort zone usually starts between 20 and 40 centimeters away and continues right up to the face, researchers report August 28 in the Journal of Neuroscience. Threatening objects that enter this forbidden space are likely to trigger a strong defensive reaction. Scientists knew that this safety margin exists, but its boundaries hadn’t been measured.