[Paleopsych] Economist: Sound economics may lie at the heart of humanity's evolutionary success

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Mon Apr 25 19:56:07 UTC 2005

Homo economicus?

Sound economics may lie at the heart of humanity's evolutionary

SINCE the days of Adam Smith and David Ricardo, advocates of
free trade and the division of labour, including this newspaper,
have lauded the advantages of those economic principles. Until
now, though, no one has suggested that they might be responsible
for the very existence of humanity. But that is the thesis
propounded by Jason Shogren, of the University of Wyoming, and
his colleagues. For Dr Shogren is suggesting that trade and
specialisation are the reasons Homo sapiens displaced previous
members of the genus, such as Homo neanderthalensis (Neanderthal
man), and emerged triumphant as the only species of humanity.

Neanderthal man has had a bad cultural rap over the years since
the discovery of the first specimen in the Neander valley in
Germany, in the mid-19th century. The “caveman” image of a
stupid, grunting, hairy, thick-skulled parody of graceful modern
humanity has stuck in the public consciousness. But current
scholarship suggests Neanderthals were probably about as smart
as modern humans, and also capable of speech. If they were
hairy, strong and tough—which they were—that was an appropriate
adaptation to the ice-age conditions in which they lived. So why
did they become extinct?

Neanderthals existed perfectly successfully for 200,000 years
before Homo sapiens arrived in their European homeland about
40,000 years ago, after a circuitous journey from Africa via
central Asia. But 10,000 years later they were gone, so it seems
likely that the arrival of modern man was the cause. The two
species certainly occupied more or less the same ecological
niche (hunting a wide range of animals, and gathering a
similarly eclectic range of plant food), and would thus have
been competitors.

Bartering for your life

One theory is that Homo sapiens had more sophisticated tools,
which gave him an advantage in hunting or warfare. Another is
that the modern human capacity for symbolic thinking (manifest
at that time in the form of cave paintings and carved animal
figurines) provided an edge. Symbolic thinking might have led to
more sophisticated language and better co-operation. But
according to Dr Shogren's paper in a forthcoming edition of the
Journal of Economic Behaviour and Organisation, it was neither
cave paintings nor better spear points that led to Homo
sapiens's dominance. It was a better economic system.

One thing Homo sapiens does that Homo neanderthalensis shows no
sign of having done is trade. The evidence suggests that such
trade was going on even 40,000 years ago. Stone tools made of
non-local materials, and sea-shell jewellery found far from the
coast, are witnesses to long-distance exchanges. That Homo
sapiens also practised division of labour and specialisation is
suggested not only by the skilled nature of his craft work, but
also by the fact that his dwellings had spaces apparently set
aside for different uses.

To see if trade might be enough to account for the dominance of
Homo sapiens, Dr Shogren and his colleagues created a computer
model of population growth that attempts to capture the relevant
variables for each species. These include fertility, mortality
rates, hunting efficiency and the number of skilled and
unskilled hunters in each group, as well as levels of skill in
making objects such as weapons, and the ability to specialise
and trade.

Initially, the researchers assumed that on average Neanderthals
and modern humans had the same abilities for most of these
attributes. They therefore set the values of those variables
equal for both species. Only in the case of the trading and
specialisation variables did they allow Homo sapiens an
advantage: specifically, they assumed that the most efficient
human hunters specialised in hunting, while bad hunters hung up
their spears and made things such as clothes and tools instead.
Hunters and craftsmen then traded with one another.

According to the model, this arrangement resulted in everyone
getting more meat, which drove up fertility and thus increased
the population. Since the supply of meat was finite, that left
less for Neanderthals, and their population declined.

A computer model was probably not necessary to arrive at this
conclusion. But what the model does suggest, which is not
self-evident, is how rapidly such a decline might take place.
Depending on the numbers plugged in, Neanderthals become extinct
between 2,500 and 30,000 years after the two species begin
competing—a range that nicely brackets reality. Moreover, in the
model, the presence of a trading economy in the modern human
population can result in the extermination of Neanderthals even
if the latter are at an advantage in traditional biological
attributes, such as hunting ability.

Of course, none of this proves absolutely that economics led to
modern humanity inheriting the Earth. But it does raise the
intriguing possibility that the dismal science is responsible
for even more than Smith and Ricardo gave it credit.


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