Life With Alacrity: The Dunbar Number as a Limit to Group Sizes
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Saved by 44 people (-7 private), first by anonymouse user on 2006-05-19
- Drichards on 2009-09-23 - Tags socialnetworking , dunbar , richardschwier , eci831
- Nobeernotv on 2009-06-25 - Tags no_tag
- Swiffs on 2009-03-27 - Tags no_tag
- Archimac on 2009-03-25 - Tags social , network , science , research , sociology , community , psychology , theory , dumbar
- Dreamingspires on 2009-03-09 - Tags dunbar's number dunbar
Public Sticky notes
Dunbar & Online Communities
Ultima Online provides one of the best examples of what sizes an online community will support because it's well documented and the overall game size is large enough to generate many smaller communities. If you look at Raph Koster's statistics for the size of groups in Ultima Online, you will see a definite point of diminishing returns at around 150; however, you will also see that most groups are around 60 large.
Highlighted by darwinianvision
... there is a cognitive limit to the number of individuals with whom any one person can maintain stable relationships, that this limit is a direct function of relative neocortex size, and that this in turn limits group size ... the limit imposed by neocortical processing capacity is simply on the number of individuals with whom a stable inter-personal relationship can be maintained.
Highlighted by cvdlinden
... there is a cognitive limit to the number of individuals with whom any one person can maintain stable relationships, that this limit is a direct function of relative neocortex size, and that this in turn limits group size ... the limit imposed by neocortical processing capacity is simply on the number of individuals with whom a stable inter-personal relationship can be maintained.
Highlighted by humbleopinion
... there is a cognitive limit to the number of individuals with whom any one person can maintain stable relationships, that this limit is a direct function of relative neocortex size, and that this in turn limits group size ... the limit imposed by neocortical processing capacity is simply on the number of individuals with whom a stable inter-personal relationship can be maintained.
Highlighted by humbleopinion
Lately I've been noticing the spread of a meme regarding "Dunbar's Number" of 150 that I believe is misunderstanding of his ideas.
Highlighted by barrosh
Dunbar is an anthropologist at the University College of London, who wrote a paper on Co-Evolution Of Neocortex Size, Group Size And Language In Humans where he hypothesizes:
... there is a cognitive limit to the number of individuals with whom any one person can maintain stable relationships, that this limit is a direct function of relative neocortex size, and that this in turn limits group size ... the limit imposed by neocortical processing capacity is simply on the number of individuals with whom a stable inter-personal relationship can be maintained.
Dunbar supports this hypothesis through studies by a number of field anthropologists. These studies measure the group size of a variety of different primates; Dunbar then correlate those group sizes to the brain sizes of the primates to produce a mathematical formula for how the two correspond. Using his formula, which is based on 36 primates, he predicts that 147.8 is the "mean group size" for humans, which matches census data on various village and tribe sizes in many cultures.
Highlighted by huangyuching
unbar is an anthropologist at the University College of London, who wrote a paper on Co-Evolution Of Neocortex Size, Group Size And Language In Humans where he hypothesizes:
... there is a cognitive limit to the number of individuals with whom any one person can maintain stable relationships, that this limit is a direct function of relative neocortex size, and that this in turn limits group size ... the limit imposed by neocortical processing capacity is simply on the number of individuals with whom a stable inter-personal relationship can be maintained.
Highlighted by drpmcgee
This number of 150 has become "Dunbar's Number" and has been popularized by various very popular business books such as Malcolm Gladwell's The Tipping Point: How Little Things Can Make a Big Difference (summary), Duncan J. Watts' Six Degrees: The Science of a Connected Age (review) and Small Worlds: The Dynamics of Networks between Order and Randomness (review), and Mark Buchanan's Nexus: Small Worlds and the Groundbreaking Science of Networks (review), the ideas from which are the foundation of the various Social Network Services that I've discussed elsewhere in this blog.
Revisiting Dunbar's Number
Lately, Dunbar's number has been taken as a mean size for online networks and groups, as shown in Ross Mayfield's Weblog, where he states:
Network Size Description Distribution
Political Network ~1000s Blogs as mass media Power-law (scale-free)
Social Network ~150 Blogging Classic Bell-curve (random)
Creative Network ~12 Blogs as dinner conversation Dense (equal)
Highlighted by ironick
Co-Evolution Of Neocortex Size, Group Size And Language In Humans where he hypothesizes:
... there is a cognitive limit to the number of individuals with whom any one person can maintain stable relationships, that this limit is a direct function of relative neocortex size, and that this in turn limits group size ... the limit imposed by neocortical processing capacity is simply on the number of individuals with whom a stable inter-personal relationship can be maintained.Dunbar supports this hypothesis through studies by a number of field anthropologists. These studies measure the group size of a variety of different primates; Dunbar then correlate those group sizes to the brain sizes of the primates to produce a mathematical formula for how the two correspond. Using his formula, which is based on 36 primates, he predicts that 147.8 is the "mean group size" for humans, which matches census data on various village and tribe sizes in many cultures.
Highlighted by paulfauth
... there is a cognitive limit to the number of individuals with whom any one person can maintain stable relationships, that this limit is a direct function of relative neocortex size, and that this in turn limits group size ... the limit imposed by neocortical processing capacity is simply on the number of individuals with whom a stable inter-personal relationship can be maintained.
Highlighted by bmevans
147.8 is the "mean group size" for humans
Highlighted by bmevans
community size of 150 will not be a mean for a community unless it is highly incentivized to remain together
Highlighted by bmevans
Dunbar's theory is that this 42% number would be true for humans if humans had not invented language, a "cheap" form of social grooming
Highlighted by bmevans
Dunbar's Number acting as a limit rather than a mean.
Highlighted by bmevans
WikiPedia
Highlighted by bmevans
that the optimal size for active group members for creative and technical groups -- as opposed to exclusively survival-oriented groups, such as villages -- hovers somewhere between 25-80, but is
Highlighted by bmevans
This all leads me to hypothesize that the optimal size for active group members for creative and technical groups -- as opposed to exclusively survival-oriented groups, such as villages -- hovers somewhere between 25-80, but is best around 45-50.
Highlighted by bmevans
This all leads me to hypothesize that the optimal size for active group members for creative and technical groups -- as opposed to exclusively survival-oriented groups, such as villages -- hovers somewhere between 25-80, but is best around 45-50. Anything more than this and the group has to spend too much time "grooming" to keep group cohesion, rather then focusing on why the people want to spend the effort on that group in the first place --
Highlighted by ctscho
Dunbar] found that the MAXIMUM number of people that a person could keep up with socially at any given time, gossip maintenance, was 150
Highlighted by bmevans
but that they only keep tabs on 150 people max at any given point
Highlighted by bmevans
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