Blink

immediately and directly at him or her because by looking at
the face, we can know — or, at least, we can know a great deal
more — about whether the sentiment is genuine. Do we see
tenderness and pleasure? Or do we catch a fleeting microexpres-
sion of distress and unhappiness flickering across his or her
face? A baby looks into your eyes when you cup your hands
over hers because she knows she can find an explanation in
your face. Are you contracting action units six and twelve (the
orbicularis oculi, pars orbitalis in combination with the
zygomatic major) in a sign of happiness? Or are you contracting
action units one, two, four, five, and twenty (the frontalis, pars
medialis; the frontalis, pars lateralis; the depressor supercilii;
the levator palpebrae superioris; and the risorius) in what even
a child intuitively understands as the clear signal of fear? We
make these kinds of complicated, lightning-fast calculations
very well. We make them every day, and we make them
without thinking. And this is the puzzle of the Amadou Diallo
case, because in the early hours of February 4, 1999, Sean
Carroll and his fellow officers for some reason could not do this
at all. Diallo was innocent, curious, and terrified — and every
one of those emotions must have been written all over his face.
Yet they saw none of it. Why?