Low IQ

As discussed in previous posts, intellectual quotient (IQ) can be mapped out using standard scores. That is, IQ follows a normal distribution with a mean of 100 and a standard deviation which can be either 15,16 or 24 for the most popular tests. What we also know from the distribution of IQ scores is that 50% of people score above 100, while 50% of scores fall below 100. The beauty of the normal distribution is that the population of IQ scores can be described using only two variables: the mean (in this case 100) and the standard deviation (either 15,16 or 24). In other words, if we know the average score and the standard deviation of the test in question, we are able to calculate the percentile score (i.e. the rank) for any given IQ test result. For instance, assuming a standard deviation of 16, we know that an IQ score of say 97 places that person at the 42.56% percentile, which means that a score of 97 is higher than roughly 42.5% of the population.

Psychologists tend to agree that an IQ score falling between 90 and 109 is considered average. Scores between 80-89 are considered ‘low average’, while scores below this are considered ‘well below average’. People with IQs below 70 were historically considered to have an mental disability or to be cognitively deficient. Roughly 26% of the population has an IQ score below 90, and about 10% of the population have an IQ score below 80. About 3% of the population will have an IQ below 70.

An IQ score of 90 is not particularly high, but it is still withing the normal range. People with IQs in the low 90s have been known to be able to secure college degrees (albeit with a lot of work and determination) An IQ of below 90 can be considered a low IQ. So what is the relevance of IQ and in particular low IQ? Well, people will low IQ are statically much more likely to struggle in school and to drop out. This in turn could expose such low IQ persons to less favorable jobs and economics prospects. Low IQ persons, on average, tend to experience greater rates of unemployment, poverty and consequently tend to also have shorter lives. Low IQ suggests that such persons will be less able to make intelligent choices when faced with tougher decisions and complex data.

Is low IQ a problem?

This depends. Many people with a low IQ in the 80s may end up living very honorable but tough lives in manual and unskilled labor. This in turn means that low IQ persons may not be able to afford the same level of education and healthcare to their children, but creates a self fulfilling prophecy of tougher environments which are likely to be less rich in opportunity for the offspring of the parents with low IQ.

This said, low IQ does not necessarily signify that individuals will be unable to live happy and fulfilling lives. Depending on how low the IQ level of course, moderately low IQ could simply be viewed as a headwind in life.

But very low IQ low 70s and below, could mean that individuals face a very serious intellectual disability which could lead to a greater requirement of intervention by caretakers. This can be a problem for the families of people with low IQs as low IQ individuals may never be capable of living fully independent lives.

Low IQ and the diagnosis of mental disability should not be made by looking at an IQ score only. People with lower levels of intellectual ability should seek a professional assessment of their condition rather than seeking out IQ testing online.