  In real world, individual rationality varies for the sake of the diversity of
people's individuality. In order to investigate how diversity of agent's
rationality affects the evolution of cooperation, we introduce the individual
rationality proportional to the $\beta$th power of the each agent's degree.
Simulation results on heterogeneous scale-free network show that the dynamic
process is greatly affected by the diversity of rationality. Both promotion and
inhibition of cooperative behavior can be observed at different region of
parameter $\beta$. We present explanation to these results by quantitative and
qualitative analysis. The nodes with middle degree value are found to play a
critical role in the evolutionary processes. The inspiration from our work may
provide us a deeper comprehension towards some social phenomenon.
