I have long thought that the
prime driver for increased intelligence was the expansion of the social
universe. This work at least begins the
task of testing those ideas although the antiquity of social systems does not
readily support that.
Likely increased intelligence made
complex social systems more possible and then merely awaited opportunity. Once larger groupings emerged, their
advantages drove the search for similar opportunities.
The surprising social systems
observed in birds and other animals, also linked to apparent intelligence begs
premature conjectures about brain size.
Why Humans Are So Sociable These Days
ScienceDaily (Dec. 20, 2011) — Humans have evolved to become the
most flexible of the primates and being able to live in lots of different
social settings sets us apart from non-human primates, suggests research by University
of Oxford and the University of Auckland.
A research paper, published in the journal Nature, has provided important
new clues to how humans network and socialise today by exploring the
evolutionary history of social groupings among primates. The study analysed
patterns of social groups among living primates, as well as examining the 'the
root' of the family tree, in 217 primate species. The researchers then used
Bayesian data modelling to reconstruct the most likely explanation for how the
grouping behaviour of primates evolved over 74 million years.
Their key finding is that the main step change in social behaviour
occurred when primates switched from being mainly active at night to being more
active during the day.
Primates started out as solitary foragers as by night[Bigfoot is
part of this - Arclein] they could
survive by moving quietly on their own in the dark. However, once they switched
to daytime activity, they could be seen and were more vulnerable to attack by
predators unless they could show strength in numbers. This research paper
provides evidence to show that this switch in activity coincided with a
significant change in social behaviour as primates started to 'gang up' for the
first time. The researchers conclude that social bonding began as a way of
adapting to a new threat.
The paper also suggests that primates went directly from being solitary
foragers into large, mixed-sex groups where group members were loosely bound
together. Members could come and go as needed, suggests the research, which is
a behaviour still observed in some primates, like lemurs, today. The emergence
of more stable groups of primates, in which individuals formed clusters that
were smaller in size and maintained close social links, is likely to have
developed much later says the paper.
These findings are significant as they throw into doubt previous
theories about the evolution of primate social grouping patterns. Previous
studies have suggested that complex primate social groups were composed of
smaller units that stacked up rather like building blocks. Others have
suggested that the bond between a mother and daughter later extended to include
other related females, and it was this network of relationships that
underpinned the social grouping patterns of mammals.
The data, studied by the research team, included a huge range of social
grouping patterns: solitary individuals, family- bonds, pair-bonds, harems, multi-male
and multi-female groups. The researchers discovered that the bonding behaviour
of primates was strongly determined by their ancestors, with closely related
species having very similar social behaviour.
Once the transition from individual to group living took place -- 52
million years ago in the ancestral line that gave rise to humans, and later in
another branch of the primate family tree -- no shift back to solitary
behaviour ever occurred. Primate ancestors that subsequently began living in
pairs did not switch back to group living, whereas those that began living in
harems could transition back and forth with large groups. There was never a
transition directly from pair to harem living or vice versa.
The researchers conclude that only humans have had the flexibility
to live in a range of different, complicated social settings. Throughout
history, humans have lived in monogamous and polygamous societies; in nuclear
family and extended family groups. Beyond the home, they have socialised in
different work settings, as well as being part of the complicated social
structure of wider human society.
Lead author Dr Susanne Shultz, from the Institute of Cognitive and
Evolutionary Anthropology at the University of Oxford, said: 'There is an
amazing flexibility in the way humans have managed to socialise, network and
live together, both in groups and wider society. We have a huge variety of
social settings to cope with, according to the different cultural practices and
customs. This flexibility in the human lineage has not evolved to anything like
this level in other primates. Our findings support previous studies that
suggest that more brain power is needed for groups that have a more complicated
social life.
'Co-author Kit Opie, also from the Institute of Cognitive
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