The Control Group is Out of Control is a popular Scott Alexander articles. In it, he examines parapsychology, the field of science that investigates such phenomenon as hypnosis, telepathy, and astral projection. If you think that psychic powers aren't real, then this is a fascinating field: it's a good example of how attempts to do science can give you the wrong answer, returning false positives. My science classes mostly focused on replicable experiments like testing acceleration due to gravity or the resistance different materials had to electricity. When studying something like telepathy or antidepressants, where not every person responds the same way, how do you sort actual effects from statistical noise?
Designed by Karl Zener in the 1930s, Zener Cards are a set of twenty-five cards with one of five different visually distinct symbols on one side. Karl Z. used them as part of a series of parapsychology experiments attempting to prove psychic powers existed; the typical experiment involved a test subject attempting to guess which card was being held by the test administrator. The experiments initially showed that some people are naturally psychic, guessing correctly more often than chance. Later experiments concluded that this was entirely down to poor experimental design. So, my question to you: are any of us psychic? What do you think you know, and how do you think you know it?
I'm bringing a couple packs of Zener cards and a couple packs of regular 52 decks. Lets do some science!