|
Roadside BanditsA clan of roadside robbers illustrates mixed evolutionarily stable strategies (MESS)SIMON SHEPPARD |
An interesting scenario can be described which combines false signals, criminality and John Maynard Smith’s notion of the evolutionarily stable strategy (ESS). It involves a clan of roadside bandits. Their tactic is to signal misfortune at the side of remote roads to waylay passing motorists and rob them. This scenario is probably more common in horror films than in actuality, but it is still a delightful example of majority and minority strategies.
In the ESS, which is defined mathematically, majority and minority strategies can co-exist, but the population following the minority strategy must remain small. Here the majority population is law-abiding motorists and the roadside bandits are, mercifully, a small minority.
The minority strategy is evolutionarily stable, according to Maynard Smith’s model of stability: suppose our bandit family were moving around a large, sparsely populated region like rural America repeatedly robbing travellers on remote roads. They could thrive and have progeny following the same strategy, the clan tradition. However their strategy is only an ESS if the population of roadside bandits remains small. If they were to grow too numerous, the majority population would become familiar with the ruse and always drive by, wary of being ambushed.
More subtle is the false signal of a police vehicle engaging its emergency lights and siren to ease its progress on a personal mission, such as fetching refreshments for an officers’ meal break, or for the mundane collection of an arrestee (this latter occurs in Britain). We can imagine the consequences of falsely issuing a distress signal from a vessel at sea, or of setting off a fire alarm in a building. Punishment would likely result, because weakening these signals is discouraged. The masculine strategy is to preserve the integrity of signals, and distress signals especially.
Sex & Power pp. 24-25