The heart icon looks nothing like a human heart. Here’s why.

Sweethearts Candy may be gone this Valentine's Day, but that shape – you know the one! – is everywhere. The iconic symbol of love looks nothing like the human organ. Why? Blame Aristotle, or maybe a plant.

The mystery of how the heart icon achieved its shape likely began in the thirteenth or fourteenth century, scholars say.

Aristotle, the ancient Greek philosopher and scientist, wrongly believed the human heart had three cavities. In fact, the heart has four chambers that pump oxygen-rich blood in and out.

Pierre Vinken, who authored The Shape of the Heart, wrote that anatomists illustrating Aristotle’s mistaken notion of what a human heart looked like might have contributed to the shape. 

By the time the anatomical error was corrected in the sixteenth century, the icon was so popular, the image stuck, Vinken wrote. 

More:Mother nature's valentine: A heart-shaped island seen from space

Another possible theory includes the heart shape mirroring the seedpods of an ancient type of silphium plant that acted as an early form of birth control in the Greek colony Cyrene.

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