{"id":516,"date":"2008-02-09T14:55:48","date_gmt":"2008-02-09T04:55:48","guid":{"rendered":"http:\/\/www.somethinkodd.com\/oddthinking\/2008\/02\/09\/mensa-membership\/"},"modified":"2008-02-09T14:55:48","modified_gmt":"2008-02-09T04:55:48","slug":"mensa-membership","status":"publish","type":"post","link":"https:\/\/www.somethinkodd.com\/oddthinking\/2008\/02\/09\/mensa-membership\/","title":{"rendered":"Mensa Membership"},"content":{"rendered":"

The topic of Mensa<\/a> society came up the other day. Since a good friend of mine joined in the early ’90s, I have been amused by their entrance criterion.<\/p>\n

Mensa “welcomes people from every walk of life whose IQ is in the top 2% of the population” [Ref<\/a>]. <\/p>\n

The normal way to qualify (in Australia, at least) is to sit two different IQ tests. <\/p>\n

One is partly verbal; the other is a so-called culture-fair test. The latter is diagram-based and depends little on knowledge of English or an English-language culture. The tests are separately marked and scored. A qualifying score in either test will get you an invitation to join Mensa. A qualifying score is a result at or above the 98th percentile — that is, a score in the range achieved by the top 2 percent of the population. [Ref<\/a>]<\/p><\/blockquote>\n

Some other countries permit two successive tests, rather than two at the same sitting. [Ref<\/a>]<\/p>\n

So, according to Mensa, if you are in the top 2% of Test 1 or<\/em> you are in the top 2% of Test 2, then you are in the top 2% of the population.<\/p>\n

Ermmmm… No, that’s not how it works. I would have thought the Mensa committee would have realised that.<\/p>\n

Passers of either of two tests are in the top 2-4% of the population: 2% if the tests are perfectly correlated (in which case there is no need for two tests), 3.96% if the tests are independent, and 4% if they are inversely correlated.<\/p>\n

I don’t know what the correlation is between the two tests provided. Wikipedia gives us some idea (with citations!) of the correlations between some IQ tests<\/a> (these are not necessarily those tests used by Mensa). They range from 0.45 to 0.81, suggesting there could be a sizeable discrepancy between the test scores.<\/p>\n

In the meantime, I am thinking Densa<\/a> might be a better fit for me.<\/p>\n","protected":false},"excerpt":{"rendered":"

In which Julian challenges the thinking of the Mensa executive.<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_s2mail":"","footnotes":""},"categories":[31,25,21],"tags":[239,70],"class_list":["post-516","post","type-post","status-publish","format-standard","hentry","category-geek","category-insufficiently-advanced-technology","category-observation","tag-iq","tag-mathematics"],"_links":{"self":[{"href":"https:\/\/www.somethinkodd.com\/oddthinking\/wp-json\/wp\/v2\/posts\/516","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.somethinkodd.com\/oddthinking\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.somethinkodd.com\/oddthinking\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.somethinkodd.com\/oddthinking\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.somethinkodd.com\/oddthinking\/wp-json\/wp\/v2\/comments?post=516"}],"version-history":[{"count":0,"href":"https:\/\/www.somethinkodd.com\/oddthinking\/wp-json\/wp\/v2\/posts\/516\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.somethinkodd.com\/oddthinking\/wp-json\/wp\/v2\/media?parent=516"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.somethinkodd.com\/oddthinking\/wp-json\/wp\/v2\/categories?post=516"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.somethinkodd.com\/oddthinking\/wp-json\/wp\/v2\/tags?post=516"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}