Languages are extremely diverse, but they are not arbitrary. Behind the bewildering, contradictory ways in which different tongues conceptualise the world, we can sometimes discern order. Linguists have traditionally assumed that this reflects the hardwired linguistic aptitude of the human brain. Yet recent scientific studies propose that language “universals” aren’t simply prescribed by genes but that they arise from the interaction between the biology of human perception and the bustle, exchange and negotiation of human culture.
Language has a logical job to do—to convey information—and yet it is riddled with irrationality: irregular verbs, random genders, silent vowels, ambiguous homophones. You’d think languages would evolve towards an optimal state of concision, but instead they accumulate quirks that hinder learning, not only for foreigners but also for native speakers.
These peculiarities have been explained by linguists by reference to the history of the people who speak it. That’s often fascinating, but it does not yield general principles about how languages have developed—or how they will change in future. As they evolve, what guides their form?