Age and Health: How They Affect IQ Test scores

Intelligence Quotient, also known as IQ, is a score that is taken from one of multiple standardized tests, with the ultimate objective of testing intelligence. There has been plenty of debate over whether or not age and health affect Studies have shown that individuals deficient in micronutrients have significant difficulty developing cognitive ability, and this correlates to lower scores on IQ tests. IQ test scores, some say it does, some say it doesn’t. People have speculated that as age declines, so does IQ test scores, and some say that as health declines, independent or dependent of age, as does your IQ test scores, but this has largely just been speculation. However, over the past few years, research has begun to bring some concrete evidence to the table, and remove the speculation and replace it with actual data.

Age as a Factor in IQ Test Performance

Research shows that as people age, their performance on IQ tests decreases. One study published in the April 2006 edition of the journal “Psychology and Aging”, which is a journal belonging to the American Psychological Association. The investigation was led by Grover C. Gilmore, of Case’s Mandel School of Applied Social Sciences. Gilmore and fellow researchers ran two experiments, testing a group of 20 year old college students, and a group of older individuals, with an average age of 70 years old. The experiments are what are referred to as coding experiments.

The results of this experiment were not shocking, if one believed the aforementioned speculation of IQ declining as age declines, as the first of the two tests showed that the college students were 34% faster than the older adults (1), which is quite a substantial difference. The younger students were over a third faster than the elderly adults at the coding tasks, which, when applied to the workplace or an academic setting, is quite a large difference.

Your Health and Your IQ Test Scores

The second factor that has been speculated to affect IQ test scores is poor health. Studies have shown that individuals deficient in micronutrients have significant difficulty developing cognitive ability, and this correlates to lower scores on IQ tests. For example, one study showed that individuals who were deficient in iodine scored on average 12 points less on IQ tests. (2) Considering the average IQ test score is 100, a 12 point drop is quite substantial, and shows that just one micronutrient deficiency can cause a significant decrease in test scores.

Improving Your Diet and Your IQ Test Results

While the research may appear to be a grim augury; that is, your intelligence will decrease as you age, and it will also decrease as your health declines, there is a bright side to this augury. Through brain exercises, and a well-balanced, proper diet, these effects can be minimized, or almost eliminated. For example, in Guatemala, a long term study was conducted which involved giving infants a high protein dietary supplement in the form of a drink. Guatemala is a country known for poor growth in infants, and this was caused by a nutritional deficiency, which in turn caused a decrease in IQ test scores. This long term study resulted in a plethora of cognitive improvements, not just in infancy, but throughout their lives. It was reported that adults up to the age of 40 had increased IQ scores as a result of this high protein dietary supplement. (3)

Even the nutrition of pregnant women can have an effect on the IQ scores of their children, as one study showed that pregnant women who consumed fish that contained fatty acids were less likely to give birth to children with lower verbal IQ test scores, among other cognitive measures such as behavioural problems and motor issues. (4) This study noted that many fish that contain fatty acids also have mercury present, which can cause mercury poisoning, but fish containing lower amounts of mercury had benefits that outweighed the slight risk of mercury poisoning. Had the mothers consumed fish that contained high amounts of mercury, the benefits would not outweigh the risk, as extremely high amounts of mercury can cause lower IQ scores due to causing mental retardation.

Exercise Your Brain

On the aging side of things, all hope is not lost either. Researchers once believed that so called mental training exercises could not increase IQ scores, but Susanne Jaeggi and her colleagues at the University of Michigan have a differing opinion, and the experimental data to back it up.

They had 70 health adults participate in their study, which involved daily training, in the form of an exercise which involved tracking squares that appeared onto a screen. (5) A similar task was performed simultaneously which involved consonants being played through headphones, and the adults had to indicate whether or not that consonant had been played two consonants ago. The adults performed this training from eight to 19 days, and their IQ was tested before the training ang again after the training.

The results were extremely positive, showing that the IQ significantly increased in individuals who received the training, and there was a correlation between the amount of training received, and the higher the score on the IQ test. While the test only involved 70 adults, the results are still very positive, and further research in this area is being planned.

Improved Health and Brain Exercises Equals Improved IQ Test Scores

So while the initial statement that IQ does decline as age increases, this can be countered by maintaining a healthy diet, and performing so called brain exercises. While you might be of average weight, that doesn’t necessarily mean that you have a healthy, well balanced diet, so it needs to be looked at with care. Your micronutrient needs might not be being met by your daily food intake, so reassessing your diet is one thing to consider, or adding a nutritional supplement which contains the needed micronutrients could be your solution. So whether you’re afraid of a lower IQ due to age, or due to health, just remember that nothing is absolute, and you have the power to change the downward slope, and maintain, or possibly even raise your IQ scores.

References to Age and Health: How They Affect IQ Test Scores

• 1) Age effects in coding tasks: Componential analysis and test of the sensory deficit hypothesis. Gilmore, Grover C.; Spinks, Ruth A.; Thomas, Cecil W. Psychology and Aging, Vol 21(1), Mar 2006, 7-18. doi:
• 2) “The effects of iodine on intelligence in children: a meta-analysis of studies conducted in China”. Qian M, Wang D, Watkins WE, et al. Asia Pacific Journal of Clinical Nutrition 14 (1) (2005). : 32
• 3) “Schooling, educational achievement, and cognitive functioning among young Guatemalan adults”. Stein AD, Behrman JR, DiGirolamo A,et al. Food Nutr Bull 26 (2 Suppl 1) (June 2005). : S46–54.
• 4) Maternal seafood consumption in pregnancy and neurodevelopmental outcomes in childhood (ALSPAC study): an observational cohort study Hibbeln JR, Davis JM, Steer C, Emmett P, Rogers I, Williams C, Golding J. (Feb 2007)
• 5) Improving fluid intelligence with training on working memory, ^ Jaeggi, S. M., Buschkuehl, M., Jonides, J., Perrig, W. J. I Proceedings of the National Academy of Sciences, vol. 105 no. 19 (2008)