In China with my family earlier this year we were walking through the thousand year old Buddhist Grotto at Dazu near Chonqing. There, meters high, carved into the rock wall was a mother feeding her young child (looked maybe 3 or 4 years old) The child was standing up, feeding from one breast and twiddling the nipple on the other side.

I could so relate! So, yes, I think children have been doing this since time began. To me, it was like nails on a chalkboard - and I quickly put a stop to it. (Twiddling - not breastfeeding - that kept going for many years!)