It is difficult to gain an understanding of language since we do not know how it is processed in the brain. Many areas of the human brain are involved in language- related activities, including syntactic operations. Aspects of the language faculty have significant heritability. There seems to have been positive selection for enhanced linguistic ability in our evolutionary past, even if most implied genes are unlikely to affect only the language faculty. Complex theory of mind, teaching, understanding of cause and effect, tool making, imitation, complex cooperation, accurate motor control, shared intentionality, and language together form a synergistic adaptive suite in the human race. Some crucial intermediate phenotypes, such as analogical inference, could have played an important role in several of these capacities. Pleiotropic effects may have accelerated, rather than retarded, evolution. In particular, it is plausible that genes changed during evolution so as to render the human brain more proficient in linguistic processing.

Natural language is a fascinating phenomenon, and it is undoubtedly partly biological. Apes, dolphins, and parrots, unlike humans, are unable to acquire language by learning, no matter how hard they try. There must be something in our genetic endowment that makes humans “ready” for language. Some people think that this readiness is simply due to higher intelligence. Although this may be true in a very broad sense, such claims do not explain how this intelligence differs from that of, say, apes. Humans seem to have gained an insight into the cause and effect in the physical domain, and we are able to produce and use tools by the so-called subassembly strategy. To us it seems that humans possess a few neural procedural capacities that are shared by several important faculties, and that these exist only in very rudimentary forms in other animals. One such procedural element is the ability to handle hierarchical structures efficiently: in the language domain, this is the recursive element of syntax; in the tool-making domain, this is the subassembly strategy; in the theory of mind domain, this is second-, third-, and fourth-order intentionality. We propose that over the past ca. 5 million years, there has been selection on several different capacities in the hominine lineage; these capacities are partly overlapping, and the intensity of selection most likely shifted (perhaps several times) over these domains. There could have been a period during which tool use and tool making were primarily favoured, but then the positively selected genetic variants could well have turned out to be favourable in some of the other critical domains.

Jezika ni preprosto razumeti, saj jezikovnega procesiranja v možganih ne poznamo. V jezikovne dejavnosti, vključno s sintaktičnimi operacijami, je vključenih veliko možganskih področij. Nekateri vidiki jezikovne sposobnosti so dedni. Kaže, da je bila v naši evolucijski preteklosti prisotna pozitivna selekcija za okrepljene jezikovne zmožnosti, čeprav večina s tem povezanih genov verjetno ne vpliva le na razvoj jezika. Kompleksne teorije uma, poučevanja, razumevanja vzrokov in posledic, izdelave orodij, imitacija, kompleksna sodelovanja, natančno motorično delovanje, skupne namere in jezik skupaj sestavljajo sinergijsko prilagodljiva človekova orodja. Verjetno so nekateri ključni vmesni fenotipi (na primer zmožnost analognega sklepanja) igrali pomembno vlogo pri nekaterih od teh zmogljivosti. Pleiotropni učinki so lahko pospešili, ne pa upočasnili evolucijo. Zlasti je verjetno, da so se geni med evolucijo spremenili tako, da so človeški možgani postali bolj sposobni za jezikovno procesiranje.

Naravni jezik je zanimiv pojav in je nedvomno delno biološko pogojen. Človekom podobne opice, delfini in papagaji – za razliko od ljudi – ne morejo pridobiti znanja jezika z učenjem, ne glede na vloženi trud. Iz tega izhaja, da mora biti v naših genih zapisana neka podpora, ki človeku omogoča učenje jezika. Nekateri menijo, da je ta pripravljenost za učenje jezika le posledica višje inteligence. Čeprav je to v zelo širokem smislu morda res, pa s tem ne moremo pojasniti, kako se človeška inteligenca loči od drugih, npr. od opičje inteligence. Zdi se, da smo ljudje pridobili sposobnost za razumevanje vzrokov in posledic v fizičnem svetu, sposobni pa smo tudi izdelovati in uporabljati orodja. Zdi se, da imamo razvitih nekaj nevronskih procesnih sposobnosti, ki so pomembne za več različnih operacij, pri drugih živalih pa so te sposobnosti bolj ali manj nerazvite. Med take elemente lahko štejemo sposobnost, da znamo učinkovito razbrati hierarhijo: na jezikovnem področju (rekurzivni element sintakse), pri izdelavi orodij in na področju miselnosti (to je namere drugega, tretjega in četrtega reda). Kaže, da je v zadnjih približno 5 milijonih let prihajalo do selekcije različnih sposobnosti pri homininih; te zmogljivosti se delno prekrivajo, intenzivnost selekcije pa se je med temi področji verjetno večkrat preusmerila. V določenem obdobju sta bili najbrž najpomembnejši uporaba in izdelava orodja, nato pa so morda pozitivno izbrane genske variante ugodno vplivale tudi na razvoj nekaterih drugih pomembnih področjih.