A learning theory is proposed which models the influence of experience on end behavior in finite Prisoner’s Dilemma supergames. The theory is compared with experimental results. In the experiment 35 subjects participated in 25 Prisoner’s Dilemma supergames of ten periods each against anonymous opponents, changing from supergame to supergame. The typical behavior of experienced subjects involves cooperation until shortly before the end of the supergame. The theory explains shifts in the intended deviation period. On the basis of parameter estimates for each subject derived from the first 20 supergames, successful predictions could be obtained for the last five supergames.