Mensa was founded in England during the 1940s as an association exclusive to intelligent individuals. To be admitted to Mensa, you must **score in the top 2 percent on one of the standardized tests** that Mensa accepts, such as Stanford-Binet, Wechsler or Cattell.

What Is Mensa?

The Mensa society is designed to provide a hub for socialization and networking among intelligent people. There is no age limit: American Mensa says it has members as young as 2. Members have access to speeches and conferences sponsored by the society; the group also sponsors scholarships and organizes community service projects.

Types of Scores and Eligibility Period

Mensa defines the type of tests accepted for membership as those testing "aptitude or ability" rather than achievement. The Iowa and California tests of basic skills, and subject-specific tests such as Advanced Placement exams, are not accepted. On the other hand, there is no expiration date on your scores: If you can produce a qualifying score from a test you took 20 years ago, Mensa will accept it. For a score to be accepted by Mensa, you need the original score or a notarized copy of the original. Many standardized tests, such as the PSAT, SAT and ACT, are accepted by Mensa, but only if they were taken before a certain date. For instance, the GRE is accepted as long as it was taken before September 2001.

Qualifying IQ Scores

Mensa defines a qualifying score on an IQ test as one that places you in the top 2 percent of the population. The exact score required depends on the test, though for most tests it is around 130. A score of 132 qualifies for the Stanford Binet and Woodcock-Johnson tests, the Reynolds Intellectual Assessment Scale, the Differential Ability Scale and the California Test of Mental Maturity. The accepted score is 130 for the Stanford Binet 5 test and any of the 14 Wechsler IQ tests. British Mensa accepts a 132 on the Cattell Culture Fair test, but a 148 is needed for the Cattell III B.

In-House Mensa Tests

If you're looking to take a test that directly qualifies you for Mensa, you can take an IQ test equivalent at one of Mensa's locations. The Mensa test is similar to the Cattell IQ test, and is designed to determine intelligence regardless of your cultural background. A small fee is required in order to take the test -- in the U.S., the cost is $40 as of time of publication. If you score in the 98th percentile -- usually around 132 -- you'll receive an invitation to Mensa. Depending on the test you take, you may also receive a report along with your test scores, evaluating your intellectual strengths.