When I was riding bikes in Scotland where I grew up every Biker waved at each other, and when I was on Holidays in America recently I noticed that it was the same there, every biker would wave when they passed. I now live in Australia and have done for the past 33 Years and riden bikes for most of that time and not one Biker has waved back at me when I have waved at them. Anti-social bunch in OZ I think