Humans can spot small signs of sickness at a glance, by using a host of facial cues – visible just hours after an infection starts – to avoid contracting illnesses from others, finds new double-blind, randomized, placebo-controlled study.

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Humans can spot small signs of sickness at a glance, by using a host of facial cues – visible just hours after an infection starts – to avoid contracting illnesses from others, finds new double-blind, randomized, placebo-controlled study.