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Brain size and intelligence

Aug 27, 1997 02:34 AM
by Philip Harris

Dallas Toenbrock, in connection Neanderthal man discusses brain
size and relates it to intelligence. It is true that brain
volume in extreme cases can be related to intelligence, but not
entirely. There are a number of factors that have to be taken
into account.

1. Cell size. The whale has a larger brain than we humans, but
the cell sizes are larger so the number of connections per neuron
is not larger in proportion.

2. Number of convolutions. The surface area of the brain is an
important factor and this is related to the number and depth of
convolutions per kg of brain. The cells (neurons?) that are
initially active in the brain are located on or near the surface
and the interior bulk is made up of cross-connections, blood
supply etc.

3. The honey bee can carry out a vast number of complex
activities such as: flying and landing with precision in strong
winds on a moving target; observe ritual displays by other bees
and deduce the distance and direction of a nectare supply; build
complex structures to contain honey and pollen and grubs;
ventilate the hive; defend the hive, etc. etc etc. It has only
about 90 neurons in its brain!

4. Some time ago there was a report about a university student
who was doing quite well in his studies, but reported to a doctor
that he was suffering headaches; a scan disclosed the fact that
his brain was the size of a small orange and had been like that
for years due to fluid compression.

5. Grey African parrots have quite small brains in comparison to
their size. recent experiments with one disclosed that the bird
was able to use, understand and compose quite grammatically
correct sentences. This requires intelligence of quite a high

These are many other factors involved such as those bearing on
brain efficiency, but those cited will, I suggest, serve to
demonstrate that it is fallacious to adopt a simplistic view of
the intelligence of any living thing- living or dead.

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