Check your subscription status, update your details and more. This question was posed as part of New Scientist’s Last Word series, in which readers give scientific answers to each other’s questions. Here’s what our readers had to say It depends what we mean by “cry”.
If we mean making a sound when distressed, humans are certainly not alone. Distress calls are widespread in the animal kingdom and are examples of an ancient form of communication. A hungry, frightened or separated youngster may attract food or protection by calling, while adults may warn others of danger.
Humans are unusual because we also cry tears. Lots of animals produce tears, but ordinarily these have nothing to do with being sad. Basal tears keep the eye moist, while reflex tears respond to irritants such as smoke or onions.
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