Why do we laugh when we are happy?

Related questions

1. How long is ielts writing test?
2. Does laughing count as talking?
3. Is fashion an art?
4. Can you die from too much laughter?
5. Is laughing a sign of happiness?
6. Is Toefl or Ielts easier?
7. Does art include music?
8. What are the forms of arts?
9. Why do I laugh at inappropriate times?
10. Can realistic art be abstract?

Tags

1. #could
2. #response
3. #start
4. #trigger
5. #positive
6. #answer
7. #purpose
8. #feelings
9. #evolutionary
10. #social
11. #people
12. #instead
13. #might
14. #function
15. #laugh
16. #provine
17. #activity
18. #around
19. #laughing
20. #other
21. #laughter