In some contexts, this idea seems to me self justifying, and probably very old indeed. I recall going fishing in the far West of Scotland with two friends, one of them a Gaelic speaking native. At the end of the day, the fish was shared into 4 equal portions, one each, plus one for the boat. I am sure the boat owner did not do this because he wanted more fish, rather, because he wished to preserve a venerable Gaelic institution, for its own sake. The tradition clearly is older than 1950 AD - it's plausibly older than 1950 BC - but would be very difficult to date it at all. More generally, I take this from memory, but I recall Keynes concluded, with some perplexity, that the basic operations of capitalism were already in place before written texts appeared, in Mesopotamia around the 3rd millennium BC. Seems to me he was right on that. Rob Tye, York, UK