Does it require intelligence to understand sarcasm and satire by an individual when they read it?

Answer 1

It's easier to get when one has the advantage of body language and vocal intonations as guides. Without them it takes an intelligent and skilled writer to make the satire or sarcasm come through clearly to the reader.

Answer 2

Unless it's a personal attack thats lacking in intelligence.

If you tell the person what they're said/written isn't polite or respectful, it's common for then to question your intelligence and continue the attack by claiming you don't understand.

Answer 3

It requires intelligence to read.
Sarcasm and satire are aquired tastes. Only slightly ajoined to inteligence.