I have argued that the cognitive capacities that are required for having iconic, first, and then, building upon the icons, symbolic representations were present in Homo erectus. This means that it is highly likely that these ancestors had some form of language that started without syntactic rules but was structured so as to mirror the structure of the world. This language undoubtedly became increasingly complex and grammatical rules started to appear to allow for the construction of more complex expressions required to keep up with the increasing complexity of their social niches. This, in turn, created evolutionary pressures that led eventually to increasing cranial size and restructuring of the brain. For the majority of researchers, the evolution of human brain and the development of language were both a response to the acquisition of symbolic thinking in a process in which all three components were intrinsically entangled.