We have in the past discussed the issue of the desirable size of an allotted chamber (or more generally, the size of the set of decision makers). The two contrasting constraints are the need for representativity on the one hand which demands the chamber is not too small, and the need to avoid mass political effects which demands that the chamber is not too big.
One important factor which determines the size at which mass political effects become influential is the ability of the group members to have face-to-face social interactions. Once group members are unable to interact with others personally, the system becomes opaque, promoting new ideas becomes increasingly difficult for the average member, and power brokering emerges. In such a situation, power is no longer equally distributed in the chamber.
It turns out that the maximum size of a group at which personal relationships are still possible has been termed “Dunbar’s number“, after British anthropologist Robin Dunbar, who theorized 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.
According to Wikipedia, the value of Dunbar’s number has been estimated to be in the range of 100 to 290. Importantly, Dunbar’s number depends on factors such as the proportion of time spent on maintaining the social relationship. Dunbar estimated that a group of 150 people would have to spend 40% of its time on maintaining personal relationships.
Presumably, with the high stakes and concentrated resources of a state parliament, the number can be pushed somewhat higher, but for lower powered chambers, the group size would have to be significantly lower for personal relationships to be sustainable.
Filed under: Sortition |