High IQ societies are for those who score in the top two percent on an official intelligence test. That is, scores at the 98th percentile or higher on a standardized, supervised IQ test are required for admission into most high intelligence societies.
Groups for those with high intelligence have been around for about as long as the intelligence test has existed. Beginning with darker roots, aimed at proving intellectual differences among citizens, they have since evolved into societies aimed at promoting education, educational advancement, and scientific research. Following the end of World War II, many high IQ societies became committed to developing into true meritocracies, devoid of discrimination based on race, sexual orientation, religion, or political affiliation.
Because there are many different IQ tests that can be used for admission, there technically isn't a minimum IQ requirement. Instead, to make it even across the board, you must score in the 98th percentile, or above, on any one of the many qualifying tests. To find the tests that are specific to the high intelligence society you want to join, contact them directly and inquire what the full scope of qualification might involve.
An IQ test usually has a mean, or arithmetic average, of 100. This means the average person scoring at the 50th percentile will achieve a score of 100 on popular IQ tests like the Stanford Binet and Wechsler Adult Intelligence Scale (WAIS).
The difference for getting into a high IQ society is that the early Stanford Binet has a standard deviation of 16 points and the WAIS has a standard deviation of 15 points. For practical purposes, this means that one would need to score a 132 or higher to gain admission based on your Stanford Binet test score. A score of 130 or higher on the WAIS would be required to achieve admission.
Those trying to gain admission could also test their abilities by taking practice tests. Practice tests are designed by those who understand the way in which intelligence tests are developed, allowing them to be of benefit to those who wish to place highly on an official intelligence test in the future. The results of the practice test will help you figure out where to channel you energies when studying, in order to achieve the highest score possible. Remember, you have to score within the 98th percentile to gain admission into most high IQ societies, so practice is key to gaining admission.
Nowadays, testing platforms are being developed to work seamlessly on both desktop and mobile, so find a platform that allows you to take the test on the go, and make the most of your free time to study and train your brain to anticipate the questions most intelligence tests deliver. Using a platform that works around your schedule, and allows you to find the materials that will help you advance your cognitive abilities will make all the difference when the time comes to attempt an official intelligence test.
Many standardized tests can be used for proof of aptitude and admission, but the organization accepting the documents decides if any standardized test can be used as a valid for of admission.
In closing, you will need to show that you have scored within the 98th percentile or higher on a standardized, proctored test of cognitive ability to join most high IQ societies. For this, it is recommended that you take practice tests and find study materials that fit the way that you learn.