I suspect that the limit involves your self-discipline and how much time you can afford to devote to study and practice, rather than genetics or IQ.
Another very important factor is psychological resilience... the ability to lose a game in horrible, embarassing fashion, then pick yourself up, shrug it off, and try again. Winston Churchill was fond of pointing out that one important ingredient to ultimate success is the ability to go from failure to failure without loss of enthusiasm.
Snowflakes make poor chess students.
Do you think that there is a genetic/physical limit to ones chess ability and in extent ones rating?
In other words do you think with enough practice anyone can become a 2000 rated player or even a master? Or does your cognitive ability create a barrier at some point?