One of the first lessons you learn in statistics is to discount first-hand experience.  “But I knew a guy who…” is weak evidence, for a long list of reasons:

1. Random error.  When you only sample one person – yourself – there’s immense random error.  The noise can easily drowns the signal.

2. Selection bias.  Are you an exactly average human?  Probably not.  In fact, exactly average humans probably simply don’t exist.  As a result, your first-hand experience systematically misrepresents reality.  And the less you resemble this average human, the greater the systematic bias.

3. Availability bias.  You are more likely to remember extreme, vivid events, so even if your first-hand experience were representative, beliefs based on your first-hand experience could still be seriously biased.


While these are all reasonable concerns, they dodge a critical question: “Compared to what?”  When someone sets aside their first-hand experience, statisticians are hoping – perhaps even assuming – that they rely on random sampling instead.  In the real world, however, almost no one does this.  For the vast majority of human beings, the alternative to first-hand experience is not statistics, but news.  And compared to news, first-hand experience is ultra-reliable, for a long list of reasons.

1. Random error.  Since the news is a vast industry, this might seem like a minor problem.  Due to severe media herding, however, the problem remains severe.  Journalists are not independent draws, but echoes in a vast echo chamber.

2. Selection bias.  Journalists are far from average humans.  They are highly-educated and highly-left-wing.  Even more importantly, they are desperately trying to grab people’s attention with shocking anecdotes and images.  What’s more, they have impressive resources to hunt down these shocking anecdotes and images.  The upshot is that media selection bias is literally off the charts.  What they choose to show is outside the first-hand experience all humans on Earth.  By which I mean that zero humans have personally experienced all – or even a tiny sliver – of the horrors on the news.

3. Availability bias.  After filtering reality through the biases of their ideology and need to grab people’s attention, journalists take the distillate and run it through yet another filter: their own memories.  So when they bring up old stories, or provide context for new stories, they are piling bias on bias.

As you may have heard, when you see moonshine marked “XXX,” this means that the liquid has been filtered three times.  Each filtration raises the alcohol content.  This is a fine metaphor for the media.  Journalists filter their experience over and over until they have a final product strong enough to make you blind.

By comparison, then, first-hand experience is a fountain of truth.  If statisticians tell you to fear something you’ve never experienced during decades of life, you may want to consider the possibility that you’ve led a charmed life.  If the media tells you the same thing, however, the wise response is to roll your eyes and rely on your first-hand experience.  While you’re not an average human, your first-hand experience almost certainty tells you that racism is rare, serious crime is ultra-rare, that terrorism is basically non-existent, and that the vast majority of people in rich countries are materially prosperous.  The media are in no position to “correct” you  – or anyone, really.  Politics aside, they are practically the most biased source on Earth.