(1/x) The human brain evolved primarily to enable complex social interactions, not rigorous math/statistical thinking. We are hardwired to place a lot of emphasis on isolated anecdotes, and social media is making this tendency very dangerous/damaging in modern world.

(2/x) There are 7.6bn people in the world. Whenever your sample size is this large, there will always be someone, somewhere, doing almost anything, including saying or doing things that are stupid or malevolent, and which invoke strong emotional responses in people that see it.

(3/x) You can therefore use an isolated anecdote to 'prove' almost anything. The danger emerges when isolated anecdotes go viral/are widely shared, and are interpreted as being representative of a broader group/social phenomenon, but might be very far from statistical average.

(4/x) Consider, for instance, that there are 800,000 police officers in the US. That is a very large n, and almost every form of police behaviour possible - from the most cruel and corrupt to the most selfless & heroic - will be happening somewhere, at some time, to some degree.

(5/x) You therefore can't infer anything about the broader systemic behaviour of the police force, for e.g, from one video of one cop doing one bad thing in one place at one particular time. It might, by chance, be representative, but it could also be very very unrepresentative.

(6/x) The danger with social media comes from it's ability to radically amplify the power of an isolated anecdote to be widely disseminated and come to be seen as a reliable and representative exemplar of a broader phenomenon.

(7/x) Even very intelligent people fall for this all the time, because human beings are hardwired - from evolutionary days where we lived in small groups - to extrapolate broad truths from individual anecdotes, which back then were far more likely to be representative.

(8/x) That does not mean anecdotes should be totally ignored. It might be representative of a broader phenomenon, & warrants investigation. But our instinct to grab our pitchforks the second we see an objectionable anecdote comporting with our (biased) world view is dangerous.