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Re2: Behaviour Bias



Responding to the message of <19970221.173509.7911.1.jamolnar@juno.com>
from jamolnar@juno.com:
> 
> On Fri, 21 Feb 1997 02:12:48 -0500 (EST) Gothgrrl@aol.com writes:
>  
> >Endocranial casts allow us to determine the ratio of brain weight to 
> >body mass, which is very, very important in determining "how intelligent" 
> >an animal may have been (or be). Good endocranial casts also allow us to
> >determine precisely how that intelligence might have manifested itself, by > 
> >demonstrating evidence of brain morphology (i.e., the size of the optic > >> 
> >lobes, frontal lobes, etc.). 
> 
> My problem is that there is no table or scale, in even extant animals,
> that will predict what behaviors you can expect with a given ratio of
> brain weight to body mass.  Even if you try this within a taxon, you
> can't get a real "ladder" of intelligent behaviors that correspond with
> the ratios.  I think you can make broad generalizations with the casts,
> from the relative sizes of optic lobes, etc, but we have no way to tell
> what behaviors were hard-wired, how flexible the learning capacity of an
> animal was, or really how to compare these things relatively among living
> animals.  An endocast is a very, very sketchy thing to base a rating of
> intelligence on.  

<Remainder of the reply has been deleted>


> Apart from the philosophical difficulties with intelligence which manifests 
itself in the controversies over the significance of IQ scales (in our own 
species), other interesting considerations can be adduced.  

It was not too very long ago that song birds were discovered to exhibit 
remarkable feats of memory, being able to recall where single seeds could be 
located among the thousands that were stored, even when the hoard was scattered 
over landscapes subsequently covered with snow.  In our attempt to assess 
ourselves by weighing various intellectual talents, conventional IQ tests have a
role for memory, or at least presuppose some mnemonic ability to achieve a high 
score.  How are we then to rate so remarkable a talent in creatures at such a 
remove from ourselves, especially in light of their lack of more creative forms 
of intellectual behavior?  

More in the realm of the latter, on TV I have seen a species of Australian 
parrot engage in symbolic behavior that was quite impressive.  Even if we could 
somehow show that it was a subtle form of rote memory, still its behavior 
presupposed a large quantity of a relatively sophisticated form of memory.  Yet 
in terms of endocranial casts, this eloquent alien creature would be dismissed 
as a mere bird-brain.  

Consider too the elaborate homing behavior of pidgeons, or for that matter 
similar behvior in mere bees, who can do such things and more on a mere 10,000 
neurons.  These considerations and examples of avian intelligence are of some 
relevance, inasmuch as birds resemble Dinosaurs at the very least, generously 
assuming, of course, that they have not themselves evolved from Dinosaurs.  We 
cannot assume, of course, that Mesozoic Dinosaurs could behave in these more 
elaborate ways, but neither can we assume on the basis of endocranial cast that 
they could not.