The simplest example is that words that are used more often—such as I, he, she, it, the, you—tend to be shorter, and consequently easier to pronounce, than less frequently used words, such as obstreperous or catafalque [ 23].
Regarding Darwin’s assertions that certain words are favoured in the ‘struggle for existence’, it is useful to remember that there is seldom any connection between a sound (a word) and its meaning. This means that selection is reasonably free to choose among words and so features of the words we actually use might reveal its actions. The simplest example is that words that are used more often—such as I, he, she, it, the, you—tend to be shorter, and consequently easier to pronounce, than less frequently used words, such as obstreperous or catafalque [ 23]. This is an example of a form of natural selection except here instead of biological individuals competing in the physical environment to survive and reproduce, words compete for space in the environment of the human mind. Our minds give preference to shorter versions of the frequently used words, presumably to reduce effort [ 23]. This pressure is relaxed among the less frequently used words, allowing them to be longer. It might also be the case that once the frequently used words have occupied the space of possible short words, there are fewer opportunities for the less frequently used words [ 24].