Discussions about salt always remind me of the story of the Russian Lykov family, who had spent 40 years living in isolation. When they were first found, they didn't even know WW2 had happened and the only gift they would accept from the outside world was salt, something they simply couldn't get enough of living in the forests of Siberia. They described living without salt as "torture".

http://www.smithsonianmag.com/history/for-40-years-this-russ...

Another video, a first contact with a tribe in Papau New Guinea, they introduce them to rice. At first they don't like it, but when they add salt, the tribe becomes excited and they share in it.

https://www.youtube.com/watch?v=xd0I1xAICOc