Laughing Rats? Panksepp & Burgdorf (2000). Behavioural Brain Research. 115, 25-38.
Conclusions:
- 50-kHz chirp serves a “social-signaling function…perhaps indicators of willingness to engage in positive social engagements (p. 38).”
- May also reflect a “positive affective process that does exist within the brains of all normal young mammals (p. 38).”
- Closely related to specifiable genetic systems.