This is the version originally submitted. It was
edited before publication.
‘Human Natures’ reflects Ehrlich’s desire to replace the static
notion of one ‘human nature’ with a celebration of the genetic and
cultural plurality of ‘human natures’. If his aim is to explore that
diversity Ehrlich certainly succeeds. He enlivens explanations of
evolutionary theory with stories from his own encounters with
chimpanzees, work with fruitflies, and adaptations in bacteria, and
moves smoothly from there to explore the fascinating history of
hominid evolution. There are descriptions of a wide variety of human
cultures and enjoyable stories of his time living with the Inuit in
the Canadian Arctic in 1952, trying to learn their language and
discovering just how different human natures can be. But this
exploration throws up many difficult questions, and not all of them
are handled well.
What is racism?
Race is a tricky issue indeed, but perhaps one better left alone
altogether than treated as it is here. For a start, the term
“racial” is placed in scare quotes and then, in a short section,
Ehrlich denies that there are any true racial groups among humans.
To support this he relies on some carefully chosen maps
demonstrating that variation in skin colour does not correlate with
variation in three other traits; average height, hair structure and
head shape. These show that “Attempts to treat divisions of humanity
based primarily on skin color as natural evolutionary units have
always been, and still are, nonsensical.” (49-52). Clearly we cannot
usefully divide human beings into a handful of distinct races
according to skin colour, but there is much more to race than this,
and much smaller groups can be, and are, described as races. So the
underlying issue is whether there are group differences in human
traits. Ehrlich gives many examples showing that there are. He
discusses the geographic distribution of traits such as lactose
tolerance, claims that the Inuit have about the largest brains of
any living people, and points out that language affects mate choice
and therefore leads to differences in gene frequencies between
different groups. Are these not, potentially at least, racial
differences?
I got the impression that in trying (quite rightly) to avoid
making judgements about superiority and inferiority, Ehrlich has
tied himself in knots. For example, it is never clear what he means
by ‘racism’ - an important problem for a book that tries to combine
a moral response to the human situation with scientific
understanding. He claims that “... racism can find no support in
science”. (p 106). I was shocked at this remark for the following
reason. Science could never provide support for racism - at least if
racism is understood as valuing some races more highly than others
or according them different rights, freedoms or responsibilities.
All science can do is to find out whether group differences exist or
not. We already know that there are differences in athletic ability
between groups; with Kenyans dominating marathon running, West
Africans excelling in 100 meter races, and some groups finding
swimming almost impossible (Entine 2000, Shermer 2000). If it turns
out to be true that some human groups are better at maths, or art or
music or learning languages this would still not be support for
racism. That is, unless simply believing in the existence of group
differences makes you a racist.
I scribbled “Naturalistic Fallacy” in the margin; that famed
tendency to confuse ‘is’ with ‘ought’. So I was surprised when,
towards the end of the book, Ehrlich himself warns his readers of
this mistake, saying “What evolved is neither good or bad: it just
is” (p 309). Yet Ehrlich seems unwilling to face the possible ‘just
is’ of group differences and consider how we can best respond. This
is surely going to be a central challenge for human political
systems and societies in the future and Ehrlich does not seem
willing to face up to it.
Do we act like our relatives?
Another tangled issue concerns to what extent genes influence
behaviour. In Chapter 1. Ehrlich derides such ideas as the genetic
tendency of Jews to be moneylenders or Asians hardworking, or the
notion that “homosexuality is in the genes” (p 22). He claims there
is a ‘fundamental error’ in statements such as “We accept that we
look like our parents and other blood relatives; we have a harder
time with the idea we act like them.” (from Hamer and Copeland 1998)
(quoted on p 7). We do indeed, but should we? Rather than tackling
this important issue, Ehrlich seems to reject the very idea that
there can be genetically based differences in sexual or other
behaviours. Yet as the book goes on, he provides us with wonderfully
illuminating examples of how genes influence behaviour; from the
edge-pupation behaviour of DDT resistant fruitflies to “Genes
predisposing individuals to schizophrenic behavior (the evidence is
quite good that such exist)” (p 218).
Ehrlich may be right that “Genes do not shout commands to us
about our behavior. At the very most, they whisper suggestions…” (p
7) but even if most of the effects are very small indeed it may yet
turn out to be true that, in some tiny measure, people from
different racial backgrounds behave a little differently, or enjoy
slightly different occupations, or that sexual orientation has a
genetic basis, even if there is no single ‘gay gene’. If so,
shouldn’t we work to understand, and even enjoy, these differences,
rather than push them under the carpet?
Does culture really evolve?
Set against the effects of genes are those of culture, and here
we come to what, in my opinion, is the major problem with this book.
Ehrlich writes at length about ‘cultural evolution’ but never makes
clear what he means by the term - and this is a serious shortcoming
for a book that is grounded in evolutionary theory and makes claims
to unify ‘genes, cultures and the human prospect’.
The problem is this. There are two major ways in which the term
‘cultural evolution’ is traditionally used. In the first, the term
is just a loose descriptive phrase more or less equivalent to
‘cultural change’. The fact that cultures change, develop, and vary
is entailed, but no particular mechanism is implied. When the term
is used this way there can be no controversy about how cultural
change works since no strong claims are made. The only controversy
concerns whether it is a appropriate to use the word ‘evolution’ at
all, since it has such a precise meaning in biology.
In the second usage, the term is much more specific. It implies
not just cultural change, but an evolutionary process driven by a
specific mechanism comparable with natural selection. Here there is
plenty of substantive controversy over such issues as whether it is
useful to think of cultural units as replicators (or indeed to think
in terms of units at all), whether variation and selection are major
forces in cultural evolution and if so how they work, how cultural
evolutionary processes can be modelled mathematically, and whether
the genes must forever keep culture on a leash (Aunger 2000, Lumsden
and Wilson 1981).
Which does Ehrlich mean? When I began reading the book I assumed
that he meant the latter, and that I was in for a challenging
exploration of how to apply evolutionary thinking to culture.
Ehrlich’s overview of evolutionary biology and human prehistory
seemed to be laying the appropriate groundwork. But in the end I had
to conclude that he means the former, for he completely fails to
commit himself to any kind of mechanism or any theory of how
cultural evolution works. Indeed the closest he comes to a
definition of cultural evolution is “a gradual change, often into a
more complex form, of the body of extragenetic information possessed
by humanity.” (p 230). He uncritically treats all of culture as part
of the ‘environment’ and does not consider the possibility that
culture is an evolving system in its own right. He does point out
that historical trajectories show many features in common with
biological evolution; giving many interesting examples of historical
events, and highlighting the way that both are influenced by
isolation and exchange, speciation and extinction. Yet he never
explains why the processes look so similar. Does culture evolve by
blind variation and selective retention? Is there a cultural
equivalent of natural selection? Is culture itself an example of
universal Darwinism at work? Ehrlich does not say.
Hope unfulfilled
Ehrlich clearly would like answers to such questions. He says:
Evolutionary theory, primarily its biological aspects, converted
biology into a coherent discipline. I have long hoped that in the
same way, evolutionary theory, primarily its cultural aspects, could
do the same for the social sciences. We badly need an evolutionary
theory of culture that unites the social sciences ... I suspect it
will take a revolution by some bright young scholars to develop such
a unifying theory. (p231).
Many others hope so too, and some have started on that project,
yet Ehrlich barely mentions them. There are probably two main
attempts here. One is the long tradition of modelling gene-culture
co-evolution by such authors as Cavalli-Sforza and Feldman, Lumsden
and Wilson, and Boyd and Richerson (see Durham 1991 for an
overview). Ehrlich includes all these in his admirably extensive
list of references but barely mentions them in the text. The other
is the more recent science of memetics built on Dawkins’s idea of
cultural units, or memes, that act as replicators and evolve by the
processes of heredity, variation and selection. This attempt Ehrlich
dismisses peremptorily in a single footnote as ‘highly speculative
literature’. There are certainly problems with the whole idea of
memes (Aunger 2000, Blackmore 1999), but at least memetics takes
seriously the idea that the whole of human culture might be a vast
evolving system, working on the same fundamental principles as
biological evolution, and with its own unpredictable (if
understandable) dynamics. Using this theory we can ask how and why
certain memes survive and reproduce, while others die out, and what
the consequences are for the people who carry and copy them. In
spite of his ‘long hope’, Ehrlich ignores these attempts while
providing us with no theory of his own.
The last chapters deal largely with moral and political issues,
and the problems of overpopulation, pollution, the breakdown of
small-group living, and the loss of biodiversity. If Ehrlich took
seriously the idea of culture as an evolving system, this might be
an opportunity to explore how runaway cultural evolution is
interacting with the biological system that gave it birth - or how
memetic evolution is causing disasters for the biological evolution
that made it possible. But since Ehrlich has no theory of cultural
evolution he has to be content with a rather general discussion of
how biologically evolved human beings are coping with excess food,
violence on television and cities built around the automobile.
Although Ehrlich warns us of terrible prospects ahead, and
implores us to think harder about human natures and our precious
environment, I think he has horribly misunderstood the true
situation. One simple sentence says it all “Cultural evolution,
unlike biological evolution, is reversible.” (p 303).
Reversible? No evolutionary process is reversible. Yes, species,
languages and traditions can go extinct. Yes, new memes can come
along that obliterate old ones - like science replacing
superstition, effective medicine replacing charms, or cars reducing
cruelty to horses, but neither biological nor cultural evolution can
go backwards. We cannot take back widespread literacy, the effects
of globalisation or the internet. Biological evolution works on
whatever material it has to hand. If cultural evolution truly is
evolution then the same applies. Moreover, we humans are parts of
the process. We cannot somehow step outside of it, or take control,
in what Ehrlich calls ‘conscious evolution’. The best we can do is
to try to understand how cultural evolution works. In this endeavour
Ehrlich does not really help.
References
Aunger, R.A. (Ed) (2000)
Darwinizing Culture: The Status of Memetics as a Science, Oxford
University Press
Blackmore,S.J.
(1999) The Meme Machine, Oxford, Oxford University Press.
Durham,W.H. (1991) Coevolution: Genes, Culture and Human
Diversity. Stanford, Ca., Stanford University Press.
Entine, J. 2000 Taboo: Why black athletes dominate sports and
why we’re afraid to talk about it. New York, Public Affairs.
Hamer,D. and Copeland,P 1998 Living with our genes. New
York, Doubleday
Lumsden,C.J. and Wilson,E.O. (1981) Genes, Mind and Culture.
Cambridge, Mass., Harvard University Press.
Shermer,M 2000 Blood, sweat and fears: Why some black athletes
dominate some sports and what it really means. Skeptic, 8:1,
44-53 (see also other articles in this special issue of Skeptic)
