> Group size is a function of relative neocortical volume in
> nonhuman primates. Extrapolation from this regression equation
> yields a predicted group size for modern humans. Groups of
> similar size are also found in other large-scale forms of
> contemporary and historical society. Among primates, the
> cohesion of groups is maintained by social grooming; the time
> devoted to social grooming is linearly related to group size
> among the Old World monkeys and apes. To maintain the
> stability of the large groups characteristic of humans by
> grooming alone would place intolerable demands on time
> budgets. It is suggested that
> (1) the evolution of large groups in the human lineage depended
> on the development of a more efficient method for time-sharing
> the processes of social bonding and that
> (2) language uniquely fulfills this requirement. It is suggested
> that language evolved to allow individuals to learn about the
> behavioural characteristics of other group members more rapidly
> than is possible by direct observation alone.
> Mean group size is directly related to relative neocortical volume
> in nonhuman primates
> there is a species-specific upper limit to group size which is set
> by purely cognitive constraints: animals cannot maintain the
> cohesion and integrity of groups larger than a size set by the
> information- processing capacity of their neocortex.
> current neocortex size sets a limit on the number of relationships
> that it can maintain through time, and hence limits the maximum
> size of its group. This means that although the evolution of
> neocortex size is driven by the ecological factors that select for
> group size, we can use the relationship in reverse to predict
> group sizes for living species
*Is there any proof that the evolution of neocortex size is driven
purely by ecological factors that select for group size? Could not the
increase of neocortex size be attributed in part to language use rather
than just the need for language?
> It is generally accepted that the cohesion of primate groups is
> maintained through time by social grooming
> ...
> The amount of time devoted to social grooming correlates well
> with group size, notably among the catarrhine primates.
>...
>(E)ffectiveness (in the sense of its members'
> willingness to come to each other's aid) is directly related to the
>amount of time its members spend grooming each other
>Groups are built up by welding together sets of smaller primary
>networks (see also Cheney 1992) and that the total size of the
>group is ultimately by the size of the networks themselves.
>...
>We can use the relationship between group size and grooming
>time to predict the grooming time required to maintain cohesion
>in groups of the size predicted for modern humans.
>...
>Modern humans would require as much as 42% of the total time
>budget to be devoted to social grooming.
>Such high grooming time requirements simply could not be met.
>there are,two solutions: either reduce group size to the point
>where the amount of grooming time is manageable or use the
>time that is available for social bonding in a more efficient way.
>Given that minimum group sizes are ecologically imposed (see
>Dunbar 1988), there may be little that a particular species can do
>to manipulate its group size in a particular habitat.
>Grooming as a bonding mechanism is highly inflexible:
>-it is all but impossible to do anything else while grooming or
>being groomed.
>-it is an essentially dyadic activity: only one other individual can
>be groomed at a time.
*Exept in the case of chain-grooming -but I guess that does not
make a significant difference.*
>Speech (can) be combined with almost every other activity,it can
>also be used to address several different individuals
>simultaneously. Thus, language introduces major savings by
>allowing an individual to do two different things at once.
>My suggestion, then, is that language evolved as a "cheap" form
>of social grooming, so enabling the ancestral humans to maintain
>the cohesion of the unusually large groups demanded by the
>particular conditions they faced at the time.
>That language (and hence speech) might have evolved as a
>consequence of the need to increase group size raises the
>question of just how it functions as a bonding mechanism.
*Is the enlargement of groups a purely ecological necessity, or could it
be attributed to the use of a possibility given by by peeviously changed
factors (language development, neocortex size),or simultanneously
changing factors.*
> Conventionally, language has always been interpreted in terms of
> the exchange of information, and this has usually been
> understood as being the exchange of information about the environment.
> However, the social intelligence hypothesis for the evolution of
> large brain size in primates implies that the acquisition and
> manipulation of social knowledge is the primary consideration.
> The fact that language can be interpreted as fulfilling the same
> role as social grooming suggests that, rather than being the
> selective factor driving brain evolution, ecologically-related
> information-exchange might be a subsequent development that
> capitalisedon a window of opportunity created by the availability
> of a computer with a substantial information-processing capacity.
*Meaning that the ecologically induced increase in group size lead
to the need to develop language to facilitate social needs, which could
only be achived by and resulted in increase in brain size, which could
then be used for a number of other things.
Is (or Can) the change in the three 'variables' be treated as subsequent
or seperate events which did not keep on affecting each-other?
> How might language function as a mechanism for social
> bonding?
> -at least two possibilities.
> 1) enabling (participants) to acquire information about each
> other's behaviour by direct observation. This appears to be one
> way in which social grooming itself might work
> 2)permit(-ing)s the acquisition of information about third party
> social relationships, thereby enabling an individual to acquire
> knowledge of the behavioural characteristics of other group
> members without actually having to observe them in action -
> considerably widening an individual's sphere of social knowledge
> relative to what would be possible from direct personal
> observation.
> If language evolved as a form of vocal its design properties
> should be of about the right efficiency. By "efficiency" here,
> I mean the number of interactants that can be simultaneously
> reached during a social interaction.
> (They) found that the average number of people directly involved
> in a conversation (as speaker or attentive listener) reached an
> asymptotic value of about 3.4.
> Results suggest that conversation does meet the requirements of
> a more efficient bonding mechanism, and that it does so at about
> the level relative to social grooming that is required to facilitate
> an increase in group size from those observed in nonhuman
> primates.
> The acquisition and exchange of information about social
> relationships is clearly a fundamental part of human
> conversation.I suggest that it implies that this was the function
> for which it evolved.
*Language as is shown, is more effective than grooming in
the sense that a larger audience or number of participants can
effectively be involved.
But this does not yet prove its effectiveness in the sharing of
information about patterns of behaviour regarding individuals not
present. Each individual, despite knowledge of them
might have to reappropriate his/her second-hand knowledge and negotiate
their relationship in interaction, as primates would have to test groom
outside their sub-groups.*
>I argued that the need to increase group size at some point
>during the course of human evolution precipitated the evolution
>of language because a more efficient process was required for
>servicing these relationships than was possible with the
>conventional nonhuman primate bonding mechanism (namely,
>social grooming).
I do not feel the NEED to increase group size justified, it might as well
have been a case of the weakening of the requirement to minimise group
size -a possibility created by neocortex size increase and/or the
development language at a level more effective than grooming as a
mechanism for social bonding.
> (3) this explanation clearly stands in direct contrast to the
> conventional wisdom that language developed in the context of
> hunting to enable early hominids to communicate about the
> location of possible prey and to plan coordinated hunting
> expeditions. Indeed, the explanation for the increase in brain size
> within the hominid lineage on which my argument is based itself
> stands in contradiction to the conventional wisdom that these
> large brains evolved to enable humans to hunt and/or
> manufacture tools.
*Meaning that, contrary to the general supposition that language
evolved to enable humans to conquer their natural environment,
it evolved to allow humans to handle their social environment,
the latter causing greater difficulties. The significance of the
thought cannot be overemphasized in my opinion, for language
which may be analysed as a social phenomena here is related to a
social origin.
It could make the arguement stronger and allow further implications if a
the increase of group size could be attributed to reasons not strictly
ecological.
> This analysis raises a number of additional questions.
> (1) At what point during the process of human evolution from
> the common pongid ancestor did such unusually large groups
> (and hence language) evolve?
> Just why early humans should have found it necessary to evolve
> such large groups remains uncertain.
This suggests that language evolved as a result of living in large
groups.Perhaps the hypothesis could slightly be modified in some ways
made reversible/invertible to allow a stronger interrelation and
more intensive interaction through time between the three factors: group
size increase, neocortx size increase and language
development/evolution rather than the mere correlation and one-
way effects between pairs of factors (as I feel the article suggests
despite its title). This way group size increase could be explained
as a gradual change made possible and supported by the increase
in neocortex size both facilitating and encouraged by language
use.
> (2) How is it that, despite these apparent cognitive constraints
> on group size, modern human societies are nonetheless able to
> form super-large groups (e.g. nation states)?
> Two observations are worth making here.
> -the structure of these super-large groupings is not particularly
> stable through time
> -language has two unusual properties that make it possible to
> form groups that are substantially larger than the 150-200
> predicted by neocortex size: it allows us
> (1) to categorise individuals into types and
> (2) to instruct other individuals as to how they should behave
> towards specific types of individuals within society. Thus, we can
> specify that individuals identified as a class by a particular badge
> (for example a clerical collar or a sherrif's badge) should be
> treated in a certain rather specific way (e.g. with great
> deference). A naive individual will thus know how to respond
> appropriately to a member of that class on first meeting even
> though s/he has never previously encountered that particular
> individual before. This may be especially important in the case of
> those types of individuals (e.g. royalty, bishops, etc) that the
> average citizen does not normally have the opportunity to meet.
> Subsequent more intimate interactions may, of course, allow the
> relationship to be fine-tuned in a more appropriate way, but
> conventional rules of this kind at least make it possible to avoid
> the initial risk of souring a potential relationship by inappropriate
> behaviour at the first meeting.
* Much of human conversation, and most of (if not all) primate
grooming, is about the negotiation of relationships (of relative
power etc.) between the participants (acc. to sociopragmatic
theory). Social knowledge (or information about social relations)
is not only gained but created, interpreted and changed through
conversation and grooming. If considered so, the value of
information gained about a third person not present, may be
lessened as relations with the third will have to be renegotiated,
which would need direct personal observation and/or
participation.*
> This ability to categorise individuals into types clearly makes it
> possible to create very much larger groups than is possible by
> direct interaction. It is only necessary to learn how to behave
> towards a general type of individual, rather than having to learn
> the nature of each individual relationship. By structuring
> relationships hierarchically in this way, social groups of very
> substantial size can in principle be built up. Notice that, even in
> this case, members of different groupings are often given
> distinctive badges or uniforms in order to allow them to be
> identified easily: this applies not only to categories of individuals
> who are considered to be "important" (e.g. officers) but also to
> members of different types of unit who are of equivalent status in
> the hierarchy (e.g. military policemen, marines, different
> regiments, etc).
*Categorization is indeed a great advantage of language, but I
would think it works in ways more complex than considered
here. Categorisation may be more effective in language but that
does not necessarily mean it only works through language.Takig
apes as an example their groups are probably divided into
categories of members according to age, sex, physical power etc.
which are marked with observable differences and of which all
members are aware. Having first hand experience of how to
behave with members of a certain category, on meeting
individuals from other groups would probably clearly be able to
identify their category and act accordingly.
> Language seems to be a far from
> perfect medium for acquiring detailed social knowledge about
> other individuals: secondhand knowledge, it seems, is a poor
> substitute for the real thing. Indeed, it is conspicuous that when
> we do want to establish very intense relationships, we tend to do
> so through the much more primitive medium of physical contact
> rather than through language. The kind of "mutual mauling" in
> which we engage under these circumstances bears a striking
> resemblance to social grooming in other primates and suffers
> from all its disadvantages.
> (3) To what extent is language a uniquely novel solution
> confined to the hominid lineage?
> The obvious analogy lies in the contact calls used extensively in
> many species of anthropoid primates to coordinate spacing
> between individuals of the same group.
> (T)he calls allow the audience to infer a great deal about the
> event or situation on which the caller is commenting, even in the
> complete absence of any visual information.
> ...
> related this ability to the social context, in particular the need to
> resolve the emotional conflicts inherent in many social situations.
> It is significant that, in the gelada, calling and counter-calling
> between individuals is closely related to the strength of the
> relationship between them.
> It may therefore be significant that gelada live in the largest
> naturally occurring groups of any nonhuman primate: the average
> size of their rather loosely structured bands (a high level
> grouping within an extended hierarchically organised social
> system based on a very much smaller stable reproductive unit) is
> about 110.
> I)t may be that the large groups in which this species sometimes
> gathers forced the evolution of a supplementary vocal mechanism
> for servicing relationships in a context where they are already at
> the limit of available grooming time
> (T)his much has been achieved without the need to increase
> neocortex size:
> This would seem to suggest that many of the basic properties of
> speech and language were already available in the more advanced
> nonhuman primates. What was required was their close
> integration and elaboration, and this may have been dependent on
> a significant increase in neocortex size in order to provide the
> necessary computing capacity.
> (T)he evolution of this increased capacity arose out of the need
> to coordinate the large number of inter-personal relationships
> necessary to maintain the cohesion and stability of larger than
> normal groups.
*This may hinder the modification of the hypothesis, to what I
would like to see, but perhaps would not make it impossible.*
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