Back to Resource Library Beyond a joke: From animal laughter to human joy? J. Panksepp · 2005 ★ NIFPlay Rating: 9 Rating Scale 10 Rigorous play-specific science 6–9 General biological science 5 Sound play research (uncontrolled) 1–4 Less rigorous / indirect 0 Indirect but high value Panksepp's analysis of ultrasonic vocalizations in rats as analogues to human laughter, arguing that joy and positive affect have deep evolutionary roots in mammalian play systems. View Resource
