Which Risks of Dying Are Worth Taking?

First, click here to figure out your chance of dying tomorrow. Is it worth taking a 1 in 100,000 chance of dying , in order to experience the novel thrill of sky diving? Is a 1 in 500,000 chance of death worth it to go bungee jumping? It's hard to know whether these risks are reasonable, because numbers like 100,000 or 500,000 feel so abstract to us. To think more clearly about these numbers, it helps to get our intuitions engaged. We can start by figuring out the daily risk of dying that...
More

Testing Too Many Hypotheses

For each dataset, there is a limit to what we can use that dataset to test. Using the standard p-value based methods of science, the more hypotheses we check against the data, the more likely it will be that some of these checks give inaccurate conclusions. And this presents a big problem for the way science is practiced. Let's take an example to illustrate the principle. Suppose that you have information about 1000 people selected at random from the U.S. adult population. Your dataset includ...
More

Surprised? Update your model.

In order to make predictions, your brain must have a model of reality. This model is necessarily much simpler than reality itself. To see why, imagine that you are about to drop a baseball from waist height. Your brain can't possibly know enough about the atoms composing that baseball and the air around it to simulate what will happen at the atomic level. And even if your brain did have accurate knowledge about the atoms, using information at such a fine a level of detail would be extremely comp...
More

(Almost) Everything is Uncertain

If you try to enumerate all of the things that you know with absolute, 100% certainty, you will find that the list is very small. You know that “something” exists. If you have mental experiences, then you know that “you” exist (though coming up with a reasonable definition for what “you” means can be remarkably tricky). If your mental experiences are varied, then you know that whatever exists creates varied mental experiences. With some cleverness, you may be able to add to this list ...
More

Finding Good Relationships Faster

For those who are interested in finding someone to date, a little probabilistic thinking can help a lot. To see how, let's take a moment to analyze the situation. Every time that you meet a new person, there is some chance that you will end up in a romantic relationship. If we want to assign a probability to this happening in any particular case, that probability will depend on the information that we know about both you and this other person. For instance, if we know that he or she is of a g...
More

Predicting Using the Past

When we try to predict how long a task will take, we are in danger of falling prey to the planning fallacy. This is the natural human tendency to underestimate how long your own projects will take and the costs involved. To give one of many possible examples, when a group of students were asked to estimate how long their senior theses would take if everything went as poorly as it possibly could, the average estimate was about 49 days. In fact, the average time it took the students to complete t...
More

Keeping Ideas at a Distance Using Probability

We often talk about ideas by using phrases like "I believe X." But what do we mean when we say that we "believe" in an idea? Do we mean that we have 100% confidence that the idea is true? Let's hope not. Even statements that we all would say we very strongly believe, like "tomorrow the sun will rise", and "I am not a robot" we should not assign 100% probability to. While we can be very, very, very certain that the sun will rise tomorrow and that our brains are not computers, we cannot be abso...
More

Truth Discernment Can be a Super Power

When we think of super powers, we usually consider things like invisibility, super strength and the ability to fly. Technology is bringing us closer to the realization of these dreams (for examples see invisibility, strength, flying). But there is a super power that has existed for much longer, which we might call "truth discernment". This is the ability to figure out what is likely to be true in hard, important, real world problems. There are difficult questions like the blue eyes logic puzz...
More