Human Limits

Exploring performance and health with Michael J. Joyner, M.D.

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Are Humans Going to Get Dumber?

This post is going to be discursive and ramble a bit, but bear with me and I think the ideas I am trying to integrate will come together for you.   In my last post I reviewed some data about how exercise can improve academic achievement in kids along with the lifetime implications of physical fitness in childhood on brain health as we age.   That got me thinking about a number of questions.


1.  Will the world get dumber as people get less active?

Here is a figure from the American Heart Association showing the percent of kids in various age groups meeting the guidelines for daily physical activity.  What will the long term implications of all of this inactivity be on the intelligence of society as a whole?  Will all of this inactivity lead to a whole lot more fuzzy old people in the future suffering from various forms of cognitive impairment as they age?




 2.  What about forms of enrichment other than exercise? 

The data on the effects of school based music lessons on cognitive performance is pretty impressive, and music education early in life seems to have long lasting effects on the brain even if you don’t continue to play and practice into adulthood.   The figure below is from the music lesson study that:


“….examined the effects of a school-based instrumental training program on the development of verbal and visual memory skills in primary school children. Participants either took part in a music program with weekly 45 min sessions of instrumental lessons in small groups at school, or they received extended natural science training. A third group of children did not receive additional training. Each child completed verbal and visual memory tests three times over a period of 18 months. Significant Group by Time interactions were found in the measures of verbal memory. Children in the music group showed greater improvements than children in the control groups after controlling for children’s socio-economic background, age, and IQ. No differences between groups were found in the visual memory tests. These findings are consistent with and extend previous research by suggesting that children receiving music training may benefit from improvements in their verbal memory skills.”




3.  What about electronics? 

The exercise and music lesson data might be interpreted in a very broad way to mean that doing things makes us smarter.   Will the same apply for our interactions with the electronic environment that surrounds and invades us?   This has been the topic of discussion in a number of venues and there are so-called smartphone holdouts who are worried that being connected to a computer will make them dumber.   For example “in the old days” people used to routinely memorize phone numbers they called frequently.   It seems to me that in the days of cell-phone speed dial and contact lists no one needs to memorize anything.   Maybe this will just free up mind space for other things, or maybe it will make us dumber because our memory needs to be used and the ability to memorize trivial things is in fact a building block for higher order thinking and intellectual skills.   In a similar vein, no one can do math in their head anymore……… those of us who grew up doing timed running or swimming workouts got very good at doing math in our heads as we calculated various split times and converted minutes to seconds depending the distance we were running or swimming.  What about video games?  A colleague of mine Dr. Bill Lanier commented that:


“My mother, who is a former college professor in education, says that if you only learn by having multi-modal input that incorporates sound, brilliant lights, movement, etc. (eg., video games), then you lose your ability to pick up a boring old book and envision what it is like to have characters move, speak, and interact.


Is the future a future with no memory, no math in our head, and no imagination?


4.  Will electronics make us less active?  

The figure below shows the interactions between screen time and physical activity and the odds of being overweight in adults.   The authors of this study concluded:


“These findings suggest that, apart from nutritional and physical activity interventions, it may also be necessary to decrease time spent in sedentary behaviors, such as leisure-time Internet and computer use, in order to reduce the prevalence of overweight and obesity………Longitudinal studies are required to examine further the potential causal relationships between the development of overweight and specific sedentary behaviors such as Internet and computer use.”





I would add the combination of no physical activity and the frequently passive nature of the electronic environment could be a double hit to our collective intelligence for the reasons outlined above.


5.  How much decision support is enough? 

The ideas above are all about the negative interactions of physical and intellectual passivity.   How far will this go?   At some the level “the machines” are increasingly taking over both routine decisions via things like collision avoidance systems in cars, but the machines are also making us potentially passive bystanders in much more important things via so-called decision support.   To take a bit of a leap, the recent debate on who decides about lethal military drone strikes highlights a number of issues about where this all might lead.  Forget for the moment the moral and ethical issues associated with killing, what constitutes the battlefield, and who is a combatant.  Imagine instead when the drones are programed with algorithms to support the remote pilots in deciding when to “pull the trigger”.   The next step will be a statistical comparison of what the humans decided to do vs. what the algorithms “suggested”.  What happens when there is no statistical difference?   What happens if evidence emerges that is pitched in the context of the drones being “more reliable”.   How soon until we give up life and death decisions to the algorithms?


6.  The end of creativity?

Another issue with decision support is that it seems to me that it can be used primarily to make the known way or ways of doing things better.  Imagine if decision support techniques had been applied to high jumping in the early 1960s.  Detailed data on the biomechanics of how people jumped, their physical characteristics, and how they trained could all be collated and the ideal higher jumper could be identified and trained accordingly and incremental improvements made.  But, what happened instead was as teenagers who “knew nothing”, Dick Fosbury and Debbie Brill, invented an entirely new way to jump that was revolutionary.  The video below if of Dick Fosbury winning the gold medal in the high jump in 1968.   Here is link to an extended to an interview with Fosbury.


click here for video



I am not sure where all of this leads us, but I am sure that humans are designed to be mentally and physically active and we should be very careful both as individuals and a species about how much we stop doing at all levels.  This includes being too physically inactive, having too much passive screen time, and turning over too many decisions to the machines.  


One Response to “Are Humans Going to Get Dumber?”

  1. February 18th, 2013 at 1:39 pm

    John says:

    Hi Mike,
    I really enjoyed this post and have no major objections to your ideas. I would like to add a couple of thoughts. First, average population IQ steadily changes over time. The Weschler IQ tests, gold standard for assessing cognitive and executive functioning, are ‘reset’ every ten years or so to keep up with the gradual upward shift in the average IQ. This shift, typically about 10 points or one standard deviation depending on the test, is thought to be due to a number of different factors from improvements in education, to better nutrition (daily vitamins, daily balanced diet).

    It is also important to have a clear understanding of what IQ means – it is not how ‘smart’ a person is (we all know people that are very intelligent at something such as math or language, but really lacking in other areas that the average person handles with ease…), it is how successful a person is able to act purposefully, think rationally and effectively interact with the environment. The Weschler tests are based on this concept of IQ, thus the test assess many areas of cognitive functioning. Other IQ theories abound, such as Gardner’s theory of multiple intelligences which includes logical-mathematical, spatial, bodily-kinesthetic, musical, interpersonal and intrapersonal. I personally think Gardner’s theories fit better with predicting success at life as opposed to success in academic achievement.

    Are we really getting dumber across our population? Dr. Gerald Crabtree at Stanford thinks so and says that we are so good at keeping people healthy even when they may have genetic mutations and these mutations are proliferating. Even a century ago, this was not the case through natural selection. Other issues could be processed foods – while we now have enough to eat on a day to day basis, is our consumption of processed foods leading to long-term impact on cognitive and executive functioning?

    As with most issues you bring up on this fascinating blog, awareness and knowledge are the keys here. If you can identify the problem, the solution often presents itself. The motivation to change diet, exercise, avoid the ‘idiot-box’, and get enough sleep is the challenge for many of us!

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