Board Thread:General Discussion/@comment-24270839-20131212055952/@comment-477304-20131222220840

I think Generations just gave descriptions of the characters, multiple Sonic games do that anyway. I don't know where Jam got that information from, but I'm guessing that they got it from the creators themselves, considering the amount of concept art and other things that can be found in the game, I do know that Knuckles was also 15 in Sonic 3 & Knuckles.