Don’t humans have bigger brains than all other animals?
No. The brains of animals such as elephants and blue whales are considerably larger than the brains of humans.
Most people therefore acknowledge that intelligence is not necessarily proportional to brain mass.
Nevertheless, many people will instead try to argue that intelligence is proportional to the ratio of brain mass to body mass, and will point out that humans have a much higher ratio of brain mass to body mass than do elephants or whales. However, the problem with this argument is that animals such as the pygmy shrew have a ratio of brain mass to body mass which is roughly equal to that of humans.
From Animal Rights and Vegetarian Ethics by Eugene Khutoryansky
I don’t see how brain size is an important issue. Does this mean that humans with larger brains can become cannibals, and eat the stupid?! 
Some animals have bigger penises… 
No, other animals have bigger brain than human… But size doesn’t affect its content, I think…