FOLK SCIENTIST

Our brain seeks corroborating evidence automatically: it optimally combines information from several sources in order to understand the world. 5 These sources are our senses. Have you ever felt that you can better hear what someone is saying when you have a line of sight to the person’s face? That is because your brain is combining vision (yes, you can lip-read!) and sound to interpret speech, and this is most important when there are distractors around (like other people talking or some background noise). 6 Another example is hammering a nail into a wall. We intuitively know that the best way to avoid hitting our thumb (or the wall) is by having it be our thumb (not someone else’s!) holding the nail. Why is that? If someone else held the nail, we would surely avoid pain to ourselves. Yet we are not as confident aiming the hammer if we are not holding the nail because vision (seeing where the nail is) is not enough. We also use the sense of proprioception—our internal knowledge, based on sensors in our joints, of where our limbs are in three-dimensional space. By holding the nail ourselves, we can combine proprioception and vision to accurately aim