Do we Really Improve with Age?

There is no debate as to whether a person's physical well-being improves with age: it does not.  When I was ten years old, and I got a cut or a bruise, it was gone without a trace within days.  Now, at the age of thirty-one, small bumps and bruises linger for weeks, even months.  It is as though my physiology has stopped trying.

When adults confront this reality, they may look on the bright side: as we grow older, we gain experience, and get smarter.  But, is there any evidence of this?  I am beginning to notice that the longer we are around, the more resistant we become to change.  And, if this is so, then our age actually becomes a deterrent for self-improvement.  A relative of mine recently pointed out that as adults age, they simply become more exaggerated versions of themselves.  Think of the seniors in your family - you may find that there is much truth to this statement.

Why do we become set in our ways?  Many reasons.  For one, the effort to improve has a smaller return on investment as we age, as there is simply less time remaining.  Another reason is that change implies we have been doing it wrong, and, the longer we have been around, the harder it becomes to face such a reality.  But, the bottom line is that change is hard because learning is hard.  Seeing the world in a new way - accepting that something is not how you always thought it was - is daunting.  It is something that students are asked to do every day, and it is so clear to me which ones wish to accept this challenge and which do not.

Pretend that you are seventeen years old, and are taking your first physics class.  The teacher explains Newton's first law of motion, which says, among other things, that a body can be in motion without any force acting on it.  You are bothered by this, as you have always felt that bodies require some kind of action in order to move.  You reject it.  Then, the teacher brings a small hovercraft into the classroom, gives it an initial kick, and you watch it glide across the room with constant speed.  Throughout this gliding, there are no forces acting on the hovercraft in its direction of motion.  Now, you are faced with a choice: you can believe what you saw and alter your understanding of the world, or you can fool yourself into remembering the demonstration wrong, and maintain your false preconception.  Many students actually choose the latter.

Harvard Physics Professor Eric Mazur has researched this phenomenon.  It turns out that a demonstration is not very effective unless students are forced to make predictions beforehand and compare these predictions to the actual outcomes afterwards.  As passive spectators, students can easily avoid the high demands that learning imposes on the brain.  Rather than 're-wiring' the brain (training themselves to see the world in a new way), they often retain a version of the demo that has been adjusted so that it aligns with their original conceptions of the laws of nature.

In my early twenties, as I busily attempted mechanics homework problems during my undergrad, I vividly remember comparing my final answer to the correct answer.  When they were the same, I was satisfied, but when they differed, I felt an initial disappointment.  Then, this kind of silly internal monologue would take place:

"Actually, it is a good thing that my initial answer was wrong.  It would be terrible if the laws of the universe altered to fit my incorrect solution.  The paint could melt from the walls and I might crumple into a ball under these new laws.  No, it is better that I conform to the actual laws than the laws conform to my error."

Ridiculous as it sounds, many of us wish the behaviour of the world would conform to our personal conceptions of it.  It is the ultimate manifestation of each individual's desire for the world to revolve around them.  I am reminded of humanity's initial rejection of a heliocentric Earth.

I believe that this difficulty we have in accepting that our own preconceived notions were false is a key reason why many deem physics to be the most difficult subject: students are introduced to physics so late in life (around seventeen).  They have used their experience to that point in their life to form certain views of the way things work, and are often unwilling to modify these views.  The views have become a part of them, and they feel defensive if these views are under attack; they choose to protect these views.  I am reminded of the feeling that some have with regard to closely held religious views, but I won't go there.

I am amazed at just how averse to learning the brain is - I mean, that is what its function is supposed to be.  In the end, if we are to improve with age, we need to accept fallibility; we must remain inquisitive, and not let our preconceptions be a barrier for knowledge.  By putting our egos aside, we allow ourselves to learn.