Sociality
Homo erectus was probably the first hominid to live in a hunter-gatherer society, and anthropologists such as Richard Leakey believe that it was socially more like modern humans than the more Australopithecus-like species before it. Likewise, increased cranial capacity generally coincides with the more sophisticated tools occasionally found with fossils.
The discovery of Turkana boy (H. ergaster) in 1984 gave evidence that, despite its Homo-sapiens-like anatomy, it may not have been capable of producing sounds comparable to modern human speech. Ergaster likely communicated in a proto-language lacking the fully developed structure of modern human language but more developed than the non-verbal communication used by chimpanzees. Such inference has been challenged by the discovery of H. ergaster/erectus vertebrae some 150,000 years older than the Turkana Boy in Dmanisi, Georgia, that reflect vocal capabilities within the range of H. sapiens. Both brain-size and the presence of the Broca's area also support the use of articulate language.
H. erectus was probably the first hominid to live in small, familiar band-societies similar to modern hunter-gatherer band-societies. H. erectus/ergaster is thought to be the first hominid to hunt in coordinated groups, use complex tools, and care for infirm or weak companions.
There has been some debate as to whether H. erectus, and possibly the later Neanderthals, may have interbred with anatomically modern humans in Europe and Asia. See Neanderthal admixture theory.
Read more about this topic: Homo Erectus