Many people claim that pets enrich their lives and make them happy, but the research on this claim is mixed.  This talk provides a review on whether pets make their owners happier. It also presents work on an understudied phenomenon—what owners do that can change their pet's dispositions and behaviors over long periods.  Much of this will focus on how researchers can reliably measure variation in animal behavior and what this variation means for human and pet happiness across the lifespan.