After how many minutes of watching video monitors does the attention of most people fall to below acceptable levels?

The correct answer is 20 minutes.

According to psychologist and philosopher William James, attention “is the clear and vivid possession by the mind of one of several simultaneously possible objects or schemes of thought. Focus and concentration of consciousness are its essence.

it´s related to his charming character.

beauty is not everything, although we can joke that girls only care about the physical or material aspect, the truth is that a real woman looks at more important things, besides intelligence and personality, there are other attitudes that make irresistible to men who are 'unattractive'.

for example develop your sense of humor.