A London judge recently banned a man from having sex with male partner, stating that his 48-point intelligence quotient (IQ) was too low to comprehend the health risks associated with "vigorous sex drive." An IQ of 48 sounds pretty low, but how low is it?

The 41-year-old man, identified only as "Alan," scored in the "moderate mental retardation" (MR) range of the Wechsler classification, which organizes IQ scores into various categories. For example, people with IQ scores between 90 and 110 are considered "normal," while those with scores between 20 and 40 are rated as having "severe MR." People that score 25 and below have "profound MR."

The lowest IQ score is hard to pinpoint because people with mental deficiencies can get very low scores because they lack the ability to comprehend the test and therefore cannot properly answer its questions. While it's theoretically possible to get a score close to zero on an IQ test, any person who would score that low wouldn't have to take an IQ test in the first place, as there are other tests designed specifically to gauge the intelligence of people with severe mental handicaps.

Alan was found to "not have the capacity to consent to and engage in sexual relations," by the judge, who ordered that Alan be closely supervised by local authorities so that he doesn't engage in sexual activity with any partners, The Telegraph reports. After ruling that Alan did not have the capability to consent to sex, the judge ordered that he undergo sex education "in the hope that he thereby gains that capacity."

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