Say what!! Fish do Consensus !?!

 

Sometimes I get told that consensus decision-making is a fad. I’m told it is based on the postmodern fallacy that there is no such thing as truth. Therefore, it is said, everyone’s opinion is as good as that of the next person. So consensus approaches supposedly just shake around this ignorance until it settles at the lowest common denominator.

Tell me about the fish!

Fish don’t know about post modernism but they do consensus decision-making. In a fascinating study reported in Current Biology Volume 18, Issue 22, p1773–1777, 25 November 2008 David Sumpter, Jens Krause, et al report on their study about fish. The fish they studied are shown to engage in a series of interactions and observations, which lead them to all take on the same course of action. Following the direction of the majority is the result of sharing information that was not known to all the individuals. Yet when it is brought together it makes sense to follow.

Consensus in Nature

There are many examples in the animal kingdom where consensus makes sense and is seen in the practice of animals.

David Sumpter and Stephen Pratt in Quorum responses and consensus decision-making; published 27 March 2009 in Royal Society Publishing observe that for many social insects, the survival of the colony depends on them remaining together and making a good decision about where to live.

For example honeybee emigration. After settling in a densely-packed swarm several hundred scout bees fly out to search for a new home. Successful scouts use the waggle dance to recruit fellow scouts to the sites they have found. Recruited bees may in turn dance for a site, creating a positive feedback loop that drives up the population of scouts visiting a site. Bees tune their dancing to the quality of the site they are advertising. Hence better sites enjoy more effective recruitment and faster population growth. Scouts periodically return to the site they are advertising and somehow assess its population. Once this exceeds a threshold value, or quorum, they return to the swarm to perform a behaviour called piping.

This process unfolds over one to several days. During this time a large number of sites are found and advertized by at least a few bees. Usually, only one site reaches quorum and induces swarm lift off. Rare split decisions have been observed. Then bees engage in an aerial tug-of-war as rival groups of scouts attempt to lead the swarm in different directions. In these cases, the bees are forced to re-settle and begin the process again.

Why consensus matters

In their article Consensus decision making in animals reported in Cell, Larissa Conradt and Timothy Roper observe that in social species many critical decisions need to be made jointly because the group will split apart unless a consensus is reached.

They look at:

  • conflict of interest between group members
  • whether they involve either local or global communication
  • different categories of consensus decision
  • who makes the decision
  • what are the underlying mechanisms
  • what are the functional consequences.

They conclude

  • consensus decision-making is common in non-human animals
  • cooperation between group members in the decision-making process is likely to be the norm
  • this is so even when the decision involves significant conflict of interest.

All the researchers acknowledge that group actions occasionally lead to incorrect decisions. However the studies show that decisions reached through consensus are often more accurate, enhance information exchange, and on average allow greater accuracy than do complete independence or weak responses to the behaviour of others.

Consensus is natural and good

Consensus building is not a fad. Deeply implanted in creation is a sense of community, and acknowledgement that we need each other. Perhaps it is the pride of Adam that keeps people wanting to play God and not work in community (which ironically is the opposite of what God does). Clearly the animal kingdom doesn’t seem to have this fault.

Consensus building is effective, efficient, natural, and the most common way decisions are made on the planet. Humans are the odd one’s out and the influence of Western individualism has only made it worse. It is time to get back to our roots and work together.