It seems so easy to strap it down, or apply pressure, or create something that would stunt its growth during adolescence. It seems like a ridiculous legend that they would chop it off... Is there any evidence at all that they would CUT off their breasts?
If I may ask a secondary question; if there is no evidence of this practice, do we know how the myth originated?
It seems like a ridiculous legend that they would chop it off...
The legend comes from a rationalisation of the name "Amazon". "Amazon" happens to look very like a Greek expression meaning "breastless", a- ("un-") + maz- ("breast"), so "Amazon" got reinterpreted as "unbreasted".
This happened several centuries after the actual origins of the legend. We start to see this reinterpretation in the 1st century BCE. The real linguistic origins of the name "Amazon" are unknown (though there are plenty of guesses).
Edit: there may be an earlier variant of this reinterpretation, though, in one of the earlier texts in the Hippocratic corpus, which may even be as early as the 4th century BC, where the women of the Sauromatae (by the Azov Sea, in Ukraine) are described as having no right breast. Here's the description of the breast-removal:
while they are yet babies their mothers make red-hot a bronze instrument constructed for this very purpose and apply it to the right breast and cauterise it, so that its growth is arrested, and all its strength and bulk are diverted to the right shoulder and right arm.
That's no good as a description of a historical Amazon society, as the Amazons were normally supposed to live in north-east Turkey, but the story's probably completely apocryphal anyway.