A kiss will make it better, or at least that's what parents tell their kids when they get hurt.
Actually not, according to Sylke Schneider-Burrus, a physician at the Charité University Hospital in Berlin, and it's not because of the childish legend.
As with sneezing and coughing, kissing or blowing on an injury could spread germs to it. Or even dry out the wound, which hinders the cells responsible for healing, as they thrive in moist environments.
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The motherly ritual may have a psychological benefit, she concedes.
For children it means attention and care, she said, adding, air movement brings some cooling and relief to the pain.