Cronyism in firms arises when favoritism toward an ingroup affects personnel decisions. Two main motives underlie cronyism: profit, if an ingroup employee works harder; or altruism, if used to transfer resources. In a lab-experiment trust game with naturally-occurring groups, an employer (proposer) faces an employee (responder) who is or is not an ingroup member. We see that both motives play a role. Cronyism is more likely from employers who are more altruistic to the ingroup in a dictator game; and even low-productivity (by design) ingroup members reciprocate trust generously. Cronyism pays for those who engage in it.