brain/body size and intelligence

John H. johnhkm at
Tue Nov 9 06:18:12 EST 1999

Brain\body ratio isn't that good. Have a look at Terrance Deacon, The
Symbolic Species, pp. 160 circa for a good overview of this subject. It
isn't going to be a single ratio, according to Deacon mice have a ratio
twice as good as us, which may explain why we still haven't wiped them out
and why they keep introducing nasty bugs to us. Maybe Gunter Grass had a
vision not a novel, the rats will win the evolutionary race after all.

Long ago I read an interesting perspective in N. Cook, The Corpus Callosum,
Mechanisms of Information ... , 1985 I think, wherein the author stated that
if you want a simple ratio consider the number of sensory fibres related to
the number of associative fibres (vertical vs. horizontal in his

So how come chiahuahus (spelling!) aren't the smartest breed? In dogs at
least brain size does not appear to match breed intelligence.

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JoshCahoon <joshcahoon at> wrote in message
news:19991108194625.04133.00002968 at
> Does anyone know why it is that the relevant data in comparing the
> of different species is brain/body ratio, rather than simply brain size?
> blue whale's brain is much larger than human brains, yet is presumably not
> intelligent as humans. Even within the human species, brain/body ratio is
> more important than brain size per se in assessing intelligence. Men's
> are, on average, larger than women's. Yet men's relatively large bodies
lead to
> about the same brain/body ratio, and hence, about the same intelligence.
To me,
> this is all  rather counterintuitive, yet I've never encountered an
> for why it is the case.

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