(Include primate, genetic, anatomical, archaeological, and petrophysical evidence)

When Language Occurred

There are three main hypotheses regarding when language occurred: upper palaeolithic with H. sapien sapien, with H. sapien, or with H. erectus.  

Some argue that the emergence of language with H. sapien sapien is found from archaeological evidence from the Upper Palaeolithic revolution with its innovative ‘explosion’ of cultural and technological artefacts. The Venus figures are carved female figurines depicting faceless and largely proportioned features. Arguably innovations such as art demonstrate a cognitive capacity like language in that they are both symbolic systems. However, Soressi and d’Erricco (2000) found crayons at a Neanderthal site which were used for body painting. Therefore, a language and art correlation indicates H. Neanderthalensis also had language. It is likely that the common ancestor H. habalis also had language 2mya.

Anatomical evidence suggests that Neanderthals had a restricted vocal range is used as evidence against them having language. Reconstructions of neanderthal skulls by Lieberman and Cremlin (1971) suggest all speech was nasalised and only short consonants could be produced. However, reconstructions of a neanderthal skulls by Houghton (1993) demonstrated that the vocal range was like modern humans. Moreover, the human hyoid bone is involved with swallowing and speech in modern humans but also poses a choking hazard. A neanderthal hyoid bone found by Arensburg et al. (1989) is in the form of the modern human shape which supports the hypothesis of a common ancestor being able to speak.

Comes from neurophysical features. Holloway (1985) found that H. Neanderthalensis endocasts revealed a Broca’s and Wernicke’s area. These areas are well known to be associated with language as portrayed in conditions of Broca’s and Wernicke’s aphasia and their impact on syntax and speech fluency. Moreover, Mithen (2006) found that modern day human brain size is like H. erectus’. As a theory by Aiello and Dunbar (1993) stated that language and brain size are directly correlated it is possible that they had language.

Genetic evidence has also been found relating to the gene FOXP2. It is widely known that a double mutation in the gene FOXP2 is associated with language. It has been shown through experiments conducted on the ‘KE family’ that language disorders specifically related to syntax is directly linked to mutations occurring in the Gene FOXP2. The same mutations that have been found in modern humans have also been identified in Neanderthals through the Neanderthal Genome Project (Krause et al., 2007)

Origin & Function

It has been argued that language may have been cooped from other adaptations already present in our ancestors such as in animal communication and or their cognitive abilities.

Evidence from primates is often used as we are closely related; specifically, Animal communication systems in the form of food calls, alarm calls and copulation calls. Cheney and Seyfarth (1990) showed that alarm calls in vervet monkeys include three calls for a leopard, an eagle, and a snake which elicit different responses such as climbing a tree for the first or hopping for the latter. They explained that although alarm calls seem to be genetically determined vervet infants showed a conceptual narrowing of the calls as they matured. Calls were narrowed into classes from categorising all land predators as a leopard to distinguishing only the leopard. This demonstrates that calls containing concepts were very likely in our ancestors too and could have been the beginnings of a vocabulary. However, Burlin (2005) argues that such alarm calls are more similar to gasps and screams in humans and it is cognitive abilities found in our primate relatives that link to language prerequisites and not their communication systems.

Neurophysical evidence like cognitive abilities such as Theory of Mind (ToM) are language precursors (Burling, 2005). ToM is the ability to recognise beliefs and intentions in others which is demonstrated in evidence of primate Machiavellian behaviours. Savage-Rumbaugh (1986) observed that when one chimpanzee was being bullied by another, the victim would make frightening noises outside enclosure and pretended to be frightened to scare their bully. Such deception needs several orders of intentionality found in ToM which demonstrates that our relatives and likely our common ancestor had ToM. The importance of ToM is recognised in communication disorders such as autism where difficulty completing a test (sally-anne) is a diagnostic in children.

Mirror neurons holds evidence for a gestural origin of language. Corballis (2003) explained that mirror neurons fire when an individual both uses motor control for grasping and when viewing grasping. He explains that non-human primates’ gesture to one another and vocalise not necessarily to individuals. He also explains that mirror neurons demonstrate a ToM as the primates are “putting themselves in the others shoes”. Savage-Rumbaugh (1998) showed a bonobo kanzi invented their own gestures to add to a taught repertoire of words. This shows a level of voluntary control not as present in animal communication as demonstrated by Jane Goodall’s observation of a chimpanzee giving a food call involuntarily when finding bananas,

Why Language Evolved

There are three key theories to why language evolved: an instrumentalist account, a social account, and a sexual account.

Pinker and Bloom (1990) argued for an instrumentalist account of language origin in that language was needed for the exchange of technical information. Primate evidence is against this theory as primate tool use such a mother chimpanzee showing her baby how to crack a nut is possible through observation and imitation. Moreover, primates are also capable of coordinated hunting without language such as chimpanzees.

However, Archaeological evidence does not support the instrumentalist account. Wynn (1988) explained that there is no correlation between tool complexity and brain size in the fossil record which would be expected given the increase in intelligence brain size yielded to solve problems. However, Pinker (1990) explains that the antiquity of language could be underestimated due to the decay of artifacts made from wood.

Neurophysical evidence from Dunbar (1998) shows that there is a causal link between neocortex size and group size in primate species; Dunbar argues for a social account of language origin. Dunbar explains that with grooming behaviours in primates facilitates bonding and that with increases in group size more grooming would be needed to maintain group cohesion. However, as grooming can only be conducted 1:1 a ceiling on group size would occur due to time constraints. Therefore, language emerged as a more efficient bonding mechanism which can be conducted 3:1. Homo sapiens group size is approximately 150 individuals and neocortex size is 4:1 which accounts for language being three times as efficient as grooming where the largest groups sizes of other primates stop at 55 individuals.

Anatomical evidence supports a social hypothesis as it argues against a sexual account of language. Sexual selection often evokes sexual dimorphism as selecting agents (females) select for attractive traits which then exponentially increase throughout a species in a process of runaway sexual selection (Fisher, 1979). Modern humans have little sexual dimorphism between the sexes, therefore this account is unlikely. However, Miller (2002) explains that language is a fitness indicator and as females are better at vocab comprehension then the language complexity could be explained as runaway sexual selection.