Why It Pays To Be Choosy: The Co-evolution Of Choosiness And Cooperation

ScienceDaily (Jan. 10, 2008) — Cooperative behaviour is common in many species, including humans. Given that cooperative individuals can often be exploited, it is not immediately clear why such behaviour has evolved.

Professor John McNamara and colleagues demonstrate that when individuals in a population are choosy about their partners, cooperativeness is rewarded and tends to increase.

Professor McNamara explained: "The problem is that the process of natural selection tends to produce individuals that do the best for themselves. So why has a behaviour evolved that appears to benefit others at a cost to the individual concerned?

In our model, an individual's level of choosiness determines the level of cooperation demanded of its partner. If the current partner is not cooperative enough the individual stops interacting with this partner and seeks a better partner, even though finding a new partner incurs costs."