I know this is incredibly old but it was on the first page of a google search I did about comparative brain size. I just wanted to say that the brain size of domestic dogs, cats, and pigs are smaller than their wild counterparts (dogs/wolves, cats/wildcats, pigs/wild boars). I suppose it is possible that our brains have become smaller as we have become more "domesticated" or "civilized". Just something that popped into my own brain while reading tonight.