In a sequential-move, finitely repeated prisoners' dilemma game (FRPD), cooperation can be sustained if the first-mover believes her opponent might be a behavioral type who plays a tit-for-tat strategy in every period. We test this theory by revealing second-mover histories from an earlier FRPD experiment to their current opponent. Despite eliminating the possibility of reputation-building, aggregate cooperation actually increases when histories are revealed. Cooperative histories lead to increased trust, but negative histories do not cause decreased trust. We develop a behavioral model to explain these findings.