[header] How to make yourself laugh [title] Use other people's laughter to trigger your own. [step] Laughter is contagious, thanks to mirroring. As you watch and listen to others laughing, your mirror neurons start to exit in a way that helps you understand the emotional experience of those laughing. 
This then primes you to begin laughing yourself. Laughing becomes even easier as others catch on and the joke becomes even more amusing.