This is the last in a series of reports from the Edinburgh International Science Festival. The talk What Makes Us Unique? was held at the Museum of Scotland.
Professor Robin Dunbar, head of the
Institute of Cognitive and Evolutionary Anthropology at the University of
Oxford and director of the innovative programme 'From Lucy to Language,' took
his audience through a brief history of the evolution of the social brain - how
cognition has contributed to our social development from being 'primate
brained' to 'human brained'.
He asked why it was that we developed from
primates rather than great apes, given that one sub-species of gorilla has more
DNA in common with humans than other gorillas. He also suggested that two
aspects of human behaviour, story-telling and religious worship, could give
important clues about how we developed.
The 'Social Brain' hypothesis arises
from chimpanzees and other primates living in a social world, which is
essentially tribal and inter-dependent. Mutual defence coalitions arise for
both extra and intra tribal protection, and mutual grooming is an important
reinforcement of these links.
Pair-bonded monogamy arises not only to foster
bi-parental care (which isn't the case with all pair-bonded species), but
essentially to promote co-ordination of activities and 'behavioural
sychronicity' (if one parent is foraging, the other is needed to care for
young, sit on eggs, protect the nest). To this extent, pair bonded animals have
a 'theory of mind' and awareness of others.
Primates exhibit more pair-bonded
social systems - the pair bond is part of a tribal society. Tribes, however,
form only one element of a complex hierarchy of groupings in humans, the upper
limit of effectiveness being around 150 persons.
Thus village populations in
England (and presumably elsewhere) remained at around 150 from the Doomsday
Book survey in the 11th century to the mid 18th. The Goretex company operates
successfully with specialist units of production with about 150 employees in
each. Elephants, chimpanzees and other primates as well as Orca whales are all
capable of dealing with 'degrees of relatedness', recognising a large number of
species members over geographical space and time, but relating to these
differently from tribal or family members.
This implies that an emotional or
relationship tie is important to cognition, that our heart in some sense rules
our brain. This in turn can reinforce how we relate to and construct our worlds
- cognition can depend on relationship up to the 5th order (I believe because
Fred told Freda, who told Harry, who told Harriet who told me).
When cognition
is direct - we think the problem through ourselves - the neurons demonstrably
work harder to achieve this. The implications of this are several - women tend
to be better at mentalising tasks, and it may be worth noting from elsewhere
that the corpus collosum, the network of neurons lying in front and between the
two lobes of our brains, is more dense and rich in neurons in women than in
men. Equally, the distribution of rods and cones in the female eyeball affords
greater sideways vision - very useful if you're watching out for predators or
venturesome young.
In the context of primate behaviour, grooming is not only a
social bonding exercise, it also releases endorphins, relaxing participants and
creating a psycho-pharmacological effect of building trust. Primates can spend
up to 1/5 of every day on grooming activity. Humans would thus need to spend
43% of their time doing this. Instead, language becomes the human substitute
for grooming, as humans use language to bond.
What, however, gives humans the
opiate kick primates gain through grooming? Professor Dunbar suggests laughter
lead to music (Inuit and other women ululate to one another, the first to laugh
being the loser of the contest), and that music in this form lead to language,
and the combination was crucial to forming religious expression.
It's known
music and religious expression are both effective in releasing endorphins - vide the 'Whirling Dervishes' of Sufi
Islam, the singing Chassidim of Judaism, the choral singing of Wales. There is,
of course, more to this, and embodied activity conducted as part of a group
leads to both feelings of well-being and group solidarity less immediately
dependent on 'endorphin kick.
Humans are capable of recognising 5th order
intention, as stated before. Primates on the other hand are probably only
capable of recognising 2nd order intention (i.e. that of one other immediate
primate). A larger corpus collosum and retinal field have obviously helped
humans, but our increased cognitive ability and social networking skills have
to be seen as a result of our cognitive past, the echo of which can be found
among our nearest relatives - the primates.
Published on EdinburghGuide.com 2008
Copyright Bill Dunlop 2008