References:

1. Elliot Aronson - coffee spilling experiment. Spilling coffee hurt the likeability of the average (or incompetent) person, but enhanced the likeability of the expert - making them appear more human and approachable.

Insights:

1. Expressing vulnerability is only effective if you are seen to be competent or an expert.
2. People prefer experts over less competent people, and pratfalls are not effective for incompetent people.
3. The self esteem of the people that view pratfalls has an impact on their effectiveness - audiences with very high or low self esteem respond less favourably to audiences with average self esteem.