How do scientists study complex emotions like jealousy in animals?

Scientists study complex emotions like jealousy in animals by creating controlled scenarios that trigger these feelings, often involving a perceived rival for attention or resources. Dogs, for example, show more attention-seeking behaviors and even aggression when their owner interacts with a realistic fake dog over inanimate objects. Researchers observe behavioral cues like gaze following, body language, and vocalizations, comparing reactions to different stimuli to discern patterns indicative of jealousy rather than simple frustration or play. They also utilize physiological measures like heart rate variability and hormone levels to identify stress responses associated with these emotions. To learn more about specific studies and species, explore our full article.