Abstract
Now a lot of Primates live in society with hierarchy system. We studied how such system evolved in the view of ‘honest’ communication.
The essence of hierarchy system is to evade struggles in groups in order to secure the profit of group formation. And a theory of asymmetrical war of attrition shows that if the strength of the individuals in a struggle and the value of the resource in dispute can be informed correctly the actual struggle is evaded, because the strategy giving up the resource immediately in the contest which does not pay is ESS. So the problem of hierarchy system returns to the problem of information.
In this study we examined the possibility that such information can be communicated by honest signal. As a result of this analysis it is revealed that i) the signal which informs the strength of the individual can evolve when the marginal cost of signal transmission is smaller for strong individual than for weak one, ii) signal which informs the value of the resource can evolve when ‘vulnerability handicap’ is supposed. These results show that hierarchy system can be explained by the combination of signaling theory and ESS of asymmetrical war of attrition.
