The same adrenaline rush was labelled as either joy or rage depending on cues
Stanley Schachter and Jerome Singer secretly injected volunteers with adrenaline, then put each one in a waiting room with an actor behaving either giddy or furious. People who weren't told what the injection would do borrowed the actor's mood, reporting euphoria or anger that matched what they'd just witnessed — even though the physical arousal was identical in every case. Their theory: emotion is raw physiological arousal plus whatever label your surroundings suggest for it.