The brain of a man weighs on average about 1.4 kilograms, while the brain of a woman with the same body size is about a hundred grams lighter, although size or weight does not indicate intelligence or brain power.
The sperm whale has the largest brain of all animals with about 9 kilograms, so it is about five times as heavy as that of humans, the orca, also killer whale, has the second largest brain of the animal world, because it weighs between 6 and 7.5 kilograms, whereby orcas are above average intelligent, which is shown for example in their hunting behavior.
Elephants also have large brains, weighing 4 kilograms, but they have significantly fewer nerve cells than humans, yet they can still perform remarkable cognitive feats, being able to remember the exact locations of watering holes within a 60-kilometer radius. They are also capable of making tools, for example, they use branches or tree trunks to scratch themselves.
The Portia spider has one of the smallest brains in the animal world, being smaller than the head of a pin and possessing just 600,000 nerve cells. Despite this, the spider is one of the most intelligent animals in the world, because it uses sophisticated hunting methods and is even able to imitate the behavior of its victims.
The most intelligent animal in the world is the chimpanzee. This is despite the fact that its brain is only one-third the size of a human’s, but they are even superior to humans in some tasks because they have an amazingly good short-term memory. In addition, they have an enormously high social intelligence.