I'd like to take a few minutes today to talk about critical thinking. I'll give a more specific definition of critical thinking later, but the main idea is that critical thinking involves examining our thought processes for assumptions and biases, and being open to revising our thinking.
First, however, I'd like to do a simple survey proposed by Philips: If anybody sitting in the audience has telekinetic powers, please raise MY hand.
Why is that funny? You assumed I would ask you to raise YOUR hands because that's how surveys typically work. When I said to raise MY hand, I said something unexpected - something that actually turned out to be a better way to assess the original proposition.
Humor is often based upon creating assumptions and then knocking them down. Groucho Marx famously quipped, "Time flies like an arrow; fruit flies like a banana." Here we are led to expect that the second use of, "flies," will be a verb, but we are amused to discover, at the end of the sentence, that we were wrong and that it was a noun.
When humorists give us assumptions that we hold briefly, we delight in letting go of them. When assumptions have been held for a long time, we don't always let go so easily.
In 2010, there was a study published by Nyhan and Reifler on something called the, "Backfire Effect." They found that when people had their incorrect beliefs challenged by evidence, they reacted irrationally. Rather than aligning their beliefs with the evidence, they became more entrenched in their incorrect beliefs.
That may sound crazy, but if you've had an argument with somebody on the other side of the political spectrum from yourself, this is probably very familiar to you. It seems these days, that everybody is right and that nobody is ever wrong. That's a shame because one of the most important things you can learn in life is how to be wrong.
This is what critical thinking is all about, and it's the one thing I hope you got out of your 4 years here. I'm not alone in this. It has been a guiding principle of education for over a century. In 1906 William Graham Sumner wrote that critical thinking is,
"the examination and test of propositions of any kind... in order to find out whether they correspond to reality or not... It is a mental habit and power. It is a prime condition of human welfare that men and women should be trained in it. It is our only guarantee against delusion, deception, superstition, and misapprehension of ourselves and our earthly circumstances.
...A teacher of any subject, who insists on accuracy and a rational control of all processes and methods, and who holds everything open to unlimited verification and revision, is cultivating that method as a habit in the pupils. Graduates educated in it cannot be stampeded... They can hold things as possible or probable in all degrees, without certainty and without pain. They can wait for evidence and weigh evidence... They can resist appeals to their dearest prejudices. Education in the critical faculty is the only education of which it can be truly said that it makes good citizens."
Whenever I happen upon that quote from Sumner, I ask myself, "Have we trained our computer scientists to be good critical thinkers?" In many ways, computer science is an excellent way to develop critical thinking. The computer does exactly what you tell it to do every single time. If your program has a bug, no amount of cajolery or sophistry will convince the computer to do otherwise. It's a cold, impartial judge. When you're wrong, you have no choice but to make a change.
But do you apply what you have learned broadly, or do you compartmentalize it, restricting what we have taught you to computer science problems? We see examples of compartmentalization everywhere. In the past year, we had an M. D. presidential candidate who did not believe in evolution. How many of you know a putatively well educated parent who avoids vaccinating his or her children despite the evidence that doing so is both safe and effective?
That's the big challenge of education. If we succeed in teaching you to think critically in a broad way, then you will respond appropriately when your assumptions are challenged in all aspects of life. This is how we hope you will avoid the dreaded backfire effect found in the Nyhan and Reifler study.
But how does education in computer science help you overcome compartmentalization? Perhaps the best thing computer science can do for you is to make you comfortable with being wrong. How many of you write code that works the first time? We all have bugs in our code but we realize it's not the end of the world. We've taught you how to make revisions that get things back on track. What I hope you all realize is that this isn't just true about code - it's true about life.
We should have a loose hold on our beliefs and be cautious about clinging to them too tightly. Our beliefs are really nothing more than the set up for a joke that the universe is telling us. When the evidence contradicts our beliefs, that's just the punchline. Embrace your wrongness, laugh at it, adjust your beliefs and move on.
If your time at Duke has taken some of the fear out of being wrong, then we've done our job and you will be better citizens for it.
I started with a joke, then explained how humor sets up expectations then dashes them. It's only fitting that I end with a joke - not any joke, but one that enjoys an evidence-based claim to be the funniest joke in the world. A website called Laugh Lab allows people to submit jokes and vote on jokes. Out of 41,000 entries and 1.5 millions votes from around the world, the following was found to be funniest:
Two hunters are out in the woods when one of them collapses. He doesn't seem to be breathing and his eyes are glazed. The other guy whips out his phone and calls emergency services. He gasps, "My friend is dead! What can I do?" The operator says "Calm down. I can help. First, let's make sure he's dead." There is a silence, then a shot is heard. Back on the phone, the guy says, "OK, now what?"
A few of you might not have found that joke funny. All I can say is that the evidence suggests that you're wrong.
Class of 2016, we've helped you develop the skills to be successful and, I hope, to be wrong. May you do both with grace and good humor. Congratulations and best wishes.