In 2011, archaeologists discovered the skeletal remains of a Roman couple who have been holding hands for 1,500 years.
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Dolphins have names for one another.
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Ten seconds of hugging a day increases levels of oxytocin, which can reduce blood pressure, thus cutting the risk of heart disease.
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Meysi is one of the world's smallest dogs, measuring in at just 7cm tall, 12cm long, and weighing a meagre 250 grams (only slightly heavier than a hamster!)
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Kissing releases masses of oxytocin, a "love potion" that helps couples bond and feel more attracted to each other.
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