Advantage at what?
A small person can fit into tight places but can't lift heavy things, and a big person can't fit into tight place but can lift heavy things.
Smart people can solve a lot of problems, but have to deal with the responsibility of carrying extra weight. More potential, more responsibility, more work.
Less intelligent people can't solve as many problems, but have to deal with the knowledge that they don't adequately carry their own weight. Less potential, less responsibility, less work.
It doesn't matter what imperfection we're talking about, it'll have some kind of advantage in some way. If you're super deformed or mentally stunted then life will be fairly easy for you, if you're symmetrical and beautiful or blessed with great mental potential then you'll have more responsibility and a harder life overall.
As a species, our diversity is our strength. Intelligence is certainly a valuable attribute, as is physical development... but there are many other attributes that define us and the enigma of the human soul reveals many mysteries to those courageous enough to search for them.
Try to see the value and important of those who are different just as much as you value those who think similarly in life, grow in every way possible.