body weight / brain weight ratio meaning proven?

[Kedas]

When referring to intelligence from different species they refer to this ratio body brain weight is there any evidence that this is a correct way of thinking.

 

Is there any relation between that ratio and intelligence of different humans?

Although I can easily find someone that is twice as smart than the other one stil they have the about same ratio.

 

Even one of the smartest people A. Einstein had a brain that weighted a lot less than average.

 

So saying that a lifeform with any size of brain is stupid is a big assumption, right?

[LucidDreamer]

Is there any relation between that ratio and intelligence of different humans?

There is only a very small correlation between brain size and intelligence.

Even one of the smartest people A. Einstein had a brain that weighted a lot less than average.

Einstein didn't have a brain size that was a lot less than average; it was average at 1230cc. Brain's shrink with age and his brain is often compared to the average brain from a person in their 20's. Factoring in shrinkage and a natural variation in brain size, he was well within average, maybe slightly below the mean.

So saying that a lifeform with any size of brain is stupid is a big assumption, right

Depends on exactly what you mean. If you were talking about an alien species then we would have no idea how their brain size related to their intelligence. If we are talking about life on earth then we can estimate intelligence from brain size, but it isn't totally reliable.

[Kedas]

Talking about earth here (since aliens is totally guessing)

You can't really say there is a very small correlation and then saying we can estimate it based on size but it isn't totally reliable.

They can't both be true. if there is only a small correlation then the estimation is almost as good as a guess.

if it's more than a small correlation then who has proven it?

 

about A. Einstein

Even if his brain size was about the same we can still easily be a factor of two different or more.

 

some info article:http://www.usaweekend.com/04_issues/040222/040222smartanimals.html

[JustStuit]

When they dig up old remains of humans they judge the brain size to show how smart they were. I think that a larger brain capacity would show that the species is smarter. But within that species the brain weight would have little to do with the intelligence.

[LucidDreamer]

You can't really say there is a very small correlation and then saying we can estimate it based on size but it isn't totally reliable.

They can't both be true. if there is only a small correlation then the estimation is almost as good as a guess.

if it's more than a small correlation then who has proven it?

There is a small correlation between brain size and intelligence within humans, so if you were to guess two random people's intelligence based on brain size you would be right more than 50% of the time.

 

Attempting to determine human intelligence based on brain size is not worthwhile because the size differences are relatively small and the characteristics of human intelligence are often hidden within the microscopic or smaller levels, though mental abnormalities leading to a mental deficiency can sometimes be seen with the eye.

 

Comparing two animal's levels of intelligence is easier because they often have very large differences in brain size and there are often big differences between the amounts of cerebral brain material, which is associated with what we call intelligence. A very large difference in brain size between two mammals is a good indication of a difference in intelligence, which has been demonstrated through research. A larger brain does not always indicate greater intelligence, especially if the animal with the larger brain has a much larger body. This is because larger mammalian bodies require larger areas of the brain associated with the senses and movement, such as the cerebellum.

For example, large whales have larger brains than human. This is where it is sometimes useful use brain size to body mass to determine intelligence.

[Kedas]

New whale tactic witnessed to catch foot: (and they are learning it to the other ones)

http://www.livescience.com/animalworld/050902_whalebait.html

imagine if whales would have books to collect the info so the next generation wouldn't always have to start over again.

[Mokele]

The answer is yes and no. Among similar species, when comparing across species, yes, it does provide a good measure. An excellent example is among primates. However, when extrapolated across broader phylogenetic lines, it breaks down rapidly, especially with species who have unusual body forms. For instance, the preditions show whales to be dumber than they really are because they have all that insulating fat, and snakes seem dumb too because the elongate body form doesn't require *that* much extra brain to run, but increases mass greatly.

 

Mokele