Answer: Spill over effect
Explanation:
Emotional volatility refers to how our emotions changes suddenly from being sad to being happy in a split of a second.
People around us can influence us with their emotions either sad or happy emotions in this case Lee was terrified for a moment but the joke made by his passenger spilled over to him which resulted to a suddenly change in which he finds himself laughing so the passengers positive emotion spilled into him and impacted him positively this is referred to as a spill over effect.