Our brain recognizes words as shapes. Consequently, if a word’s shape is easy to recognize (i.e., its shape is somewhat unique), the time required to process that word is fast. With this in mind, here’s where the way things actually work is counter-intuitive.

Because many short words are similar, their shape is not always easy to recognize. The words ‹met› and ‹net,› for example, are similar in shape and take a longer time for your brain to process than longer words, which have a higher probability of not being similar in shape to other words. In essence, the shorter the word, the more likely your brain will require additional processing to pinpoint exactly which word you are looking at. This requires longer processing times than it takes to process words with more characters.

Maik Maurer.