‘Tis the season for holiday planning. It can be a stressful time: do we visit the museums? Or the beach? It’s easy for one person – and even two, three or four people – to decide what to do. But as the group gets larger, human beings become unable to reach a consensus. The result is often that one person seems to get his or her way but it doesn’t have to be. Why? When it comes to mass planning, more is different.
More Is Different was the title of a 1972 paper by the Princeton University physicist Philip Anderson. What he meant was that individual behaviour is different to group behaviour. You can’t always understand something by taking it apart and examining the properties and proclivities of its constituent parts. That is true whether you’re talking about a collection of atoms, people, or – as Iain D Couzin is doing this month – baboons.
Couzin, also at Princeton, researches group behaviour in animals. He is in London to give a conference talk at the Science Museum. The meeting covers a swath of “emergent” group behaviours: the emergence of resistance to antibiotics, for instance. One bacterium can’t develop it but a group achieves it together. Then there is the flocking behaviour of starlings and the swarming of locusts.
Spacecrafts can also be built to show emergent behaviour. Flying in adaptable formations and following simple rules, much like flocks of birds, they can navigate obstacles and find landmarks or landing sites more efficiently. Atoms that group together in ways dictated by simple forces can also display complex emergent properties. Superconductivity, the ability to conduct electricity without energy-sapping resistance, is one. Superfluidity, which allows helium atoms to defy gravity and flow up the walls of a container, is another.
It’s likely that some processes within our bodies are emergent phenomena. Couzin’s work has suggested that memory and recognition rely on co-ordinated activity between groups of neurons, raising the possibility that dementia may mark a failure of emergent phenomena in the brain. It is possible that other emergent phenomena regulate our physical health; if we can get a handle on these, they may open the door to new treatments.
But the promise that comes from studying emergent properties is not just medical or technological – it is also societal. Watching the behaviour of primates, aware of their lack of language, we usually imagine one individual dictating to the group. Couzin’s most recent research suggests we couldn’t be more wrong. In a paper published in the journal Science last month, Couzin and his co-workers showed that baboons won’t follow a despotic leader.
Like people, baboons live in groups with close but complex social bonds. Individuals have varying skills and different levels of dominance – some are alphas, some decidedly not. Yet when it comes to important decisions about the future, everyone has an equal voice, if they choose to use it. When a call has to be made about, say, where to look for food or water, many offer suggestions. If a proportion of their proposed paths align closely enough, a solution emerges. Couzin’s team showed that the direction taken is a compromise: the average of the closely aligning suggestions.
It’s an enticing prospect. Remember, evolution is the master of stumbling upon optimal solutions. If you’re fed up with despotic holiday planners, band together and be more baboon.