Kissing releases masses of oxytocin, a "love potion" that helps couples bond and feel more attracted to each other.
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When cats are happy, they may squeeze their eyes shut.
10
In 2011, archaeologists discovered the skeletal remains of a Roman couple who have been holding hands for 1,500 years.
81
Dolphins have names for one another.
18
Ten seconds of hugging a day increases levels of oxytocin, which can reduce blood pressure, thus cutting the risk of heart disease.
26
A puppy is born blind, deaf, and toothless.
16