One of my grand-daughters and her little brother both started playing a wingbone at 2 years old. I could not believe how quickly they caught on. I've always said that I could teach someone in half the time that had never tried them before. Sometimes bad habits are hard to break.
Once at a show in Tenn., a vendor next to me had a young son, I'd guess about 4-5 years old. He asked about the wingbones and how to play them so we sat down and in no time he was playing it pretty doggone good. Every time someone would ask about how hard they were to play, I'd call the little guy over, stand him up in a chair and let him go at it. When they heard that I'd just taught him, they bought one. I sold ever wingbone I had that weekend except for the one I gave the little guy.
Fred