you have kifosis lord12 if you havnt noticed yet but its not a high degree the problem is that your upper body (from a little above the ribcage) is pushed backwards slightly making your chest look...
i say even minimal work is better then no work at all, if you dont do anything and say "when i get this and that ill do this and that" like so many of us do
it might happen but theres a lower...
if thats what he means then low body fat does count towards having them but other then that its purely genetics since its not a muscle that you can work on