Why,
among the myriad species of social animals on this planet do we humans,
uniquely (as far as we know), have culture? Half a million years ago early
hominids would have lived in social groups much as we observe higher
primates, chimpanzee in particular, now. Then something must have happened
to trigger the transition from social to cultural. What was that trigger and
what were the processes and mechanisms of the transition? How did the
earliest proto-cultural behaviours emerge and take hold, and what were
those behaviours?
These
are deep questions that are extremely difficult to answer, not least because
the archaeological record tells us almost nothing of the
processes and mechanisms of the emergence of culture. But why and how do we
have culture? is surely a Big Question. A question that notably transcends
discipline boundaries. An answer would profoundly deepen understanding of our
origins as a cultural species, and therefore the human condition, and - if
the processes by which culture emerges turn out to be generalisable to other
species - we would have an insight into how we might recognise culture in
non-human species, including aliens and robots.
Theories
of cultural evolution broadly fit into two camps: one holds that culture is
merely an adaptation and that genes will always, as E.O. Wilson put it
"hold culture on a leash". The other and more controversial Memetic
theory of cultural evolution holds that culture is not an adaptation but
instead an accidental by-product of humans' capacity for imitation that has, according to S.J. Blackmore's The Meme Machine, taken off on its own evolutionary trajectory and is now more-or-less independent of genes. The
culture-is-just-an-adaptation theory is, for me at least, the less interesting
and persuasive of the two; in saying this I - a fully paid-up disciple of
Ockam - am acutely aware that the memetic theory is the less
ontologically parsimonious. But sometimes the right explanation is
not simplest and, tantalisingly, the memetic theory may turn out to be
testable.
In
a nutshell, the memetic theory goes something like this.
1. Early hominids evolved the ability to
imitate each other. It is reasonable to speculate that imitation has strong survival
value since if you are a good imitator then you can copy someone else's learned
behaviour and therefore save yourself the effort of learning that behaviour
from scratch. The important distinction here is between social learning (and
imitation is one way to do social learning), and individual learning; social
learning costs much less effort than individual learning. The
thing-that-is-imitated and hence passed from the originator to the copier is
called a meme. (Note that imitation doesn't necessarily imply cooperation.)
2. As soon as the imitation skill is
sufficiently refined and widespread, then memes are able to persist in the
population. In fact, memes will experience (a) mutation, since it's more or
less impossible to copy something perfectly, (b) selection, since the meme
imitators will selectively copy some memes over others, and (c) heredity,
since a single meme could be copied, then the copy may be in turn copied over
multiple (meme) generations. Thus, as soon as the society of meme originators
and meme copiers has collectively reached some minimum threshold of imitation
skill (including sufficient fidelity of imitation), then memes will evolve in
that society according to Darwinian processes of natural
selection, except that this is now memetic evolution.
3. When the society reaches this stage then
an important transition has been crossed. Up until that point those early
hominids evolved only by means of genetic evolution. But as soon as memes are
able to persist and evolve then there are two parallel evolutionary processes:
genetic and memetic; this is so called meme-gene co-evolution. After this
transition, the theory argues, being an effective meme copier confers a premium
in the game of sexual selection. Any genetic mutation that improves imitation
skill will be differentially selected, giving rise to a richer environment for
memes to evolve, which in turn improves the likelihood of meme copiers mating
and - it is conjectured - a runaway cycle of meme-gene co-evolution resulted in
big-brained hominids that are exquisitely skilled and artful imitators. Since
the imitation skill can imitate anything, and since the most compelling memes
will gain a strong foothold, then culture can now emerge with all of its kaleidoscopic
variety: art, music and dance, ritual and religion, language and
technology.
According
to the memetic theory imitation is a prerequisite behaviour necessary for
the evolution of culture. But what other prerequisites are needed? One,
arguably, is communication. Language clearly has a pivotal role in human
culture, but is language an outcome of the evolution of culture, or a
prerequisite? Many social animals communicate, even animals with very small
brains (relative to mammals); think of bees communicating the location of
pollen. And primates appear to have a complex repertoire of calls which, in
the case of chimpanzee combine with body language and facial expression to
allow the sophisticated communication of emotional states. Since imitation need
not involve communication, or indeed cooperation, it's not at all clear whether
communication is a necessary prerequisite or an extraordinary beneficiary; my
own view is that some minimal level of communication is a prerequisite (turn
taking and attention seeking or giving, for instance) but that the co-evolution
of high fidelity imitation and memes provided the springboard for the language
instinct in humans.
Another
prerequisite perhaps, is theory of mind: the ability of one individual to
build a internal model of another's intentions. It's well known that
chimpanzee have sophisticated social behaviours which demonstrate so called
Machiavellian intelligence; the matriarchal Bonobo are a remarkable
example. One individual might for instance become friends with another not
because they want to be friends, but in order to gain social advantage; the
fraudulently befriended might have friends that they really want to get to
know. Success in these complex social interactions requires an individual to
have an internal model of not just one but a number of other members of the
group and, at some level, be able to ask 'what if' questions: "What if I
make friends with...?"; "Should I be assertive or passive?",
"How should I respond if s/he tries to make friends with me?". My
view is that theory of mind - in the sense of Machiavellian intelligence - is
not a prerequisite for culture (but that may just be because I can't figure out
how and where it might fit into the co-evolutionary processes). Of course you
could also argue that imitation is itself a simple form of theory of mind,
because the very act of imitation implies that the copier confers agency to the
copied and of course requires that the copier builds some kind of representation
of the meme in its brain.
When
discussing prerequisites we must not overlook the environment. It's hard to imagine that environmental factors
like climate change, predators, competitors or disease wouldn't play a
part in triggering or catalysing the transition from social to cultural; some
trauma that provided additional evolutionary pressures which differentially
favoured imitation and innovation. Perhaps forest dwelling hominids with abundant
food and no predators (as gorilla would be if it were not for man) had to
be evicted - as it were - by environmental pressures from their evolutionary
garden of eden to trigger the transition to culture.
Returning
to the question that forms the title of this essay, the answer to the question
Why, is I believe, easier. My own view is that the reason we humans have
culture is, quite simply, because we can. The fact that we have culture is of
course, in itself, an existence proof that culture can emerge in social
animals. The reason that it did, in our species, is - I would argue - because
of an entirely contingent (and probably rather unlikely) combination of
circumstances. In other words the right behavioural and environmental
prerequisites were present over a sufficiently long time period to allow
the engine of memetic evolution to splutter into life. The question How remains a big and unanswered question.
Postscript:
An answer to the question How is currently being attempted. A research project
in the UK is attempting to build a society of robots, create the conditions
(prerequisites), and then free-run that artificial society in the hope that
proto-cultural behaviours will emerge. The project is extremely challenging for
several reasons. The first, already discussed above, is to determine the
initial conditions: the behavioural and environmental prerequisites. The second
challenge is to programme the robots with the prerequisite behaviours and
create an artificial environment for the robot society. The third and perhaps
greatest challenge is, when this artificial society is free-run will anything
interesting emerge at all and, if it does, will it be recognisable and robustly
interpretable as evidence for culture, given that it will of course be robot-,
not human-culture. The methodological starting point for this project is the
memetic theory of cultural evolution and the project therefore offers the possibility,
for the first time, of experimental validation of that theory