I have no bone straight "haired" friends. My one friend is like a 2a/2b if she let it dry naturally, but she brushes it to oblivion... My other friend is a 4a like me.
And we talk about natural hair because she just went natural. I have another friend who is like a 3b/3c, she is always dying her hair it feels like. My boyfriend did have a fro, but then he cut it off.
I think his hair would be about a 3c maybe 4a if he let it grow out and took care of it. It grows out straight wayyy before curly.