So, were the Neandertals humans? I’ve uncovered some data which may shed light on this question.
There are some creationists (notably, Hugh Ross and Fazale Rana) who believe that only Homo sapiens qualifies as truly human, meaning that the Neandertals were brute beasts, lacking rational souls – a view that is difficult to square with evidence presented by Dediu and Levinson, in their paper, On the antiquity of language: the reinterpretation of Neandertal linguistic capacities and its consequences (Frontiers in Psychology, 4:397. doi: 10.3389/fpsyg.2013.00397), indicating that they possessed language.
The Neandertals managed to live in hostile sub-Arctic conditions (Stewart, 2005). They controlled fire, and in addition to game, cooked and ate starchy foods of various kinds (Henry et al., 2010; Roebroeks and Villa, 2011). They almost certainly had sewn skin clothing and some kind of footgear (Sørensen, 2009). They hunted a range of large animals, probably by collective driving, and could bring down substantial game like buffalo and mammoth (Conard and Niven, 2001; Villa and Lenoir, 2009).
Neandertals buried their dead (Pettitt, 2002), with some but contested evidence for grave offerings and indications of cannibalism (Lalueza-Fox et al., 2010). Lumps of pigment — presumably used in body decoration, and recently found applied to perforated shells (Zilhao et al., 2010) — are also found in Neandertal sites. They also looked after the infirm and the sick, as shown by healed or permanent injuries (e.g., Spikins et al., 2010), and apparently used medicinal herbs (Hardy et al., 2012). They may have made huts, bone tools, and beads, but the evidence is more scattered (Klein, 2009), and seemed to live in small family groups and practice patrilocality (Lalueza-Fox et al., 2010).
Professor Nathan H. Lents, in a 2015 blog article, has also argued that Neandertal man was capable of speech, although he concedes that Homo erectus was probably incapable.
I should point out, however, that Dediu and Levinson’s 2013 paper has been critiqued by Berwick, Hauser and Tattersall, who argue in their commentary that: (i) “hominids can be smart without implying modern cognition”; (ii) “smart does not necessarily mean that Neanderthals had the competence for language or the capacity to externalize it in speech”; (iii) the earliest unambiguous evidence for symbolic communication dates from less than 100,000 years ago; and (iv) although they may have had the same FOXP2 genes as we do, “[n]either Neanderthals nor Denisovans possessed human variants of other putatively ‘language-related’ alleles such as CNTAP2, ASPM, and MCPH1.”
Recent evidence seems to bear out the authors’ skepticism about the Neandertals’ use of language. Scientists at the 2017 annual meeting of The American Society of Human Genetics discussed the significance of Neandertal genes, pointing out that “some ‘Neandertal’ genetic variants inherited by modern humans outside of Africa are not peculiarly Neandertal genes, but represent the ancestral human condition,” according to a report by Ann Gibbons in Science magazine (October 23, 2017). But there was more. New findings strongly suggest that the Neandertals would have suffered some severe speech impediments, if they spoke at all:
Other geneticists at the meeting zeroed in on archaic DNA “deserts,” where living humans have inherited no DNA from Neandertals or other archaic humans. One of these regions includes the site of the FOXP2 “language” gene. This suggests that in our ancestors, natural selection flushed out the Neandertal version of this gene. Using statistical software that evaluates gene expression based on the type of gene, Vanderbilt graduate student Laura Colbran found that Neandertal versions of the gene would have pumped out much less FOXP2 protein than expressed in modern brains. In living people, a rare mutation that causes members of a family to produce half the usual amount of FOXP2 protein also triggers severe speech defects, notes Simon Fisher, director of the Max Planck Institute for Psycholinguistics in Nijmegen, the Netherlands, who discovered the gene. Expression of FOXP2 may be key to language, Fisher says.
If we define the “human-making” attributes as language and a theory of mind, these appear to have originated with our species, Homo sapiens. Symbolic art, science and religion seem to be unique to our species as well, although there is evidence that the Neandertals buried their dead.
If instead, we choose to define the “human-making” attributes as self-control and morality, then it would seem to have originated with Heidelberg man. I’d like to draw readers’ attention to Benoit Dubreuil’s well-argued essay, Paleolithic Public Goods Games: Why Human Culture and Cooperation Did Not Evolve in One Step (Biology and Philosophy (2010) 25:53–73, DOI 10.1007/s10539-009-9177-7). Dubreuil’s claim is that the human prefrontal cortex reached its present form about 700,000 years ago, with the appearance of Heidelberg man, whose advanced prefrontal cortex conferred on him “modern-like abilities for inhibitory control and goal maintenance.” In plain English, Heidelberg man’s advanced pre-frontal cortex meant that he was able to control his selfish impulse to turn tail and run from dangerous predators, and put his own life at risk in order to defend the “greater good” of the group; additionally, he was able to make long-term plans and commitments relating to his and his family’s future. These advances, Dubreuil believes, would have allowed Heidelberg man to hunt big-game (which is highly rewarding in terms of food, if successful, but is also very dangerous for the hunters, who might easily get gored by the animals they are trying to kill) and make life-long monogamous commitments (for the rearing of children whose prolonged infancy and whose large, energy-demanding brains would have made it impossible for their mothers to feed them alone, without a committed husband who would provide for the family) became features of human life. Dubreuil refers to these two activities as “cooperative feeding” and “cooperative breeding,” and describes them as “Paleolithic public good games” (PPGGs). He believes that Homo erectus lacked these abilities: while there’s good evidence that he ate a lot of meat, there’s no good evidence that he hunted large-scale game. Dubreuil thinks he was probably an active scavenger, which means that he ate meat from carcasses that other animals had killed, and confronted any creature that tried to stop him eating.
However, even Dubreuil acknowledges that the distinctive features of Homo sapiens‘ brain enabled modern man to make further cognitive advances, relating to theory of mind, language, symbolism and art. These advances, Dubreuil believes, were triggered by developments in the temporoparietal cortex of the brain, rather than the prefrontal cortex:
One of the most distinctive features of Homo sapiens’ cranium morphology is its overall more globular structure. This globularization of Homo sapiens’ cranium occurred between 300 and 100,000 years ago and has been associated with the relative enlargement of the temporal and/or parietal lobes (Lieberman et al. 2002; Bruner et al. 2003; Bruner 2004, 2007; Lieberman 2008). Paleoneurological reconstructions are currently insufficient to identify the precise regions that benefited from globularization. It is not unreasonable, however, to link this change with a functional reorganization of the higher association areas of the temporal and parietal areas…
The temporoparietal cortex is certainly involved in many complex cognitive tasks. It plays a central role in attention shifting, perspective taking, episodic memory, and theory of mind (as mentioned in Section “The role of perspective taking”), as well as in complex categorization and semantic processing (that is where Wernicke’s area is located)…
I have argued elsewhere (Dubreuil 2008; Henshilwood and Dubreuil 2009) that a change in the attentional abilities underlying perspective taking and high-level theory of mind best explains the behavioral changes associated with modern Homo sapiens, including the evolution of symbolic and artistic components in material culture.
Finally, there are no clear-cut boundaries between Australopithecus and early Homo, between early Homo and Homo erectus, between Homo erectus and Heidelberg man, and between Heidelberg man and Neandertal man. However, there is one species whose appearance in the fossil record is relatively sudden: Homo sapiens. As Ian Tatterall and Jeffrey Schwartz put it in their article, The morphological distinctiveness of Homo sapiens and its recognition in the fossil record: Clarifying the problem (Evolutionary Anthropology, Volume 17, Issue 1, pp. 49-54):
Species are historically differentiated entities that, osteologically, may be differentiated to inconveniently varying extents. Living Homo sapiens is a distinctive morphological entity that is easily distinguished in both cranial and postcranial morphology from all other living hominoids and from the vast majority of its fossil relatives.
So when did we become human? Recent discoveries have pushed the origin of Homo sapiens back to at least 300,000 years ago, and we still don’t know if this was a sudden or a gradual event. On the other hand, the great leap forward in human culture seems not to have taken place until about 100,000 years ago, which is when modern human behavior emerged in South Africa. This seems to have been a relatively sudden event.
I’d like to make a final suggestion regarding the evidence for Neandertal art. Is it possible that this art post-dated contact between Neandertals and Homo sapiens, and that some Neandertals picked it up from us? Just an idea.