All you need to do to join Mensa is to demonstrate your intelligence by taking a standardized test such as the GMAT or other tests and score in the top 2 percentile. Then fill out an application on their website to gain membership.
In order to be a member of MENSA you have to prove you have an above average IQ and impeccable test scores. Once this is noticed by an education board or scholastic institution, you will be notified and invited.
I believe that you have to have a certain IQ or intelligence level. You might have to take a test sponsered by MENSA to find out what it is, or supply them with a reliable score.
