If every life bearing planet follows Darwins theory and neurology follows the same rules possibly following the whole brain needs oxygen and other supplements to properly function then is it possible that the basic layout of their brains and body chemistry followed a more sophisticated advanced way. To get oxygen to the brain quicker or in larger quantities at a time of course proportionally so that it wouldn't be to much oxygen for the brain to handle at once and who's to say their brains even follow the common earthly need for oxygen maybe they've converted to using a more dense gas that our brains couldn't handle but theis eat it up quick enough to not harm them thus giving them a healthier more "nutritious" flow to the brain in return making them smarter and if its a planet with less gravity then theoretically the neurons can move throughout their brains faster making connections quicker just as light in space travels faster than it does on earth due to air molecules friction and gravity but gravity is the stressor of these and once again following earth neurology which could highly differ from other world s they may have more aggression than us as well aggression fuels intelligence those who have had mother's who had a substancial amount of stress during pregnancy will statistically have higher IQ.kids and kids with major to severe aggression problems from ages. 13-18 statistically have an IQ boost of about 16 points its a portion of the brain linked to aggression and those with larger parts of that segment of the brain generally have higher IQ's as well and look around us our closest predecessor is the chimp I believe with an average IQ of 70 or so point being this cells transform modify die out and the product you are left with is the most suitable in its own environment now let me ask you something have cells really had to transform and modify neurologically to survive on this planet Answer:not really in fact the experimental Lucy was pretty much the first and one of the last now its just humans who are developed neurologically on this planet but what if on another planet the importance of neurological development was realized much sooner and was spread out from our equivalence of the fish coming out of water if so a good 60% could be intelligent enough to produce systems as we do but from looking at our own planet one can only skepticize that intelligence is rare if so we might actually be in luck my final conclusion is that if there is another intelligent species chances are what will come knowing each and everyone of our luck it will be a real life reinactment of an episode off of the twilight zone