“What does my bookshelf tell you about me?”
“What can you deduce from my handwriting?”
“Giving you just this one photo, what can you glean?”
You get one picture and a challenge in the subreddit “Science of Deduction”. Nearly 1,500 people post here, all fancying themselves a Sherlock Holmes, or wishing to become more like him. The entire section is a user’s picture and a question like those above. Some of the deductions other users make using only a picture are surprisingly spot-on, others aren’t. But users are happy to offer advice and answer each deduction, right or wrong, in the hopes of becoming more like their favorite, brainy hero.
Why did a section like Science of Deduction spring up? Well, aside from the incredible success of the BBC series, we are right to envy Sherlock Holmes. His mind is unfettered, uncluttered in a way ours are not. He can resist the sway of emotion, has a seemingly inexhaustible supply of attention, and processes information for days in a way that most of us can only do for minutes. (For more on cognitive bias and the brilliance of Sherlock Holmes, check out my post in Scientific American.)
Of course, there is no “science” of deduction, but deductive reasoning is still the lifeblood of science. Deductive reasoning is the process of using general principles to make specific claims about the world. For example, we know that copper conducts electricity. If you see a copper wire laying around, you can deduce that the wire will conduct electricity.
Deduction works best when the general principles you work from are as steady as the conduction of electricity, and gets trickier when trying to quantify trends in human behavior. Still, if you try observing the world, and not just seeing it—as Sherlock urged Watson in “A Scandal in Bohemia”—you might be surprised how much truth you can squeeze from the smallest details.
So, why not let a group of strangers on the Internet look inside your house for a bit?
Think you can deduce like Sherlock Holmes? Check out /r/scienceofdeduction and prove it right now.
Kyle Hill is the Science Officer of the Nerdist enterprise. Follow the geekery on Twitter @Sci_Phile.