Language is a cornerstone of human culture, yet the evolution of this cognitive-demanding ability is shrouded in mystery. Studying how different species demonstrate this trait can provide clues for its evolutionary route. Indeed, recent decades saw ample scientific attempts to compare human speech, the prominent behavioral manifestation of language, with other animals’ vocalizations. Diligent studies have found only elementary parallels to speech in other animals, fortifying the belief that language is uniquely human. But have we really tested this uniqueness claim? Surprisingly, a true impartial comparison between human speech and other animals’ vocalizations has hardly ever been conducted. Here, I illustrate how treating humans as an equal species in vocal-communication research is expected to provide us with no evidence for human superiority in this realm. Thus, novel balanced and unbiased comparative studies are vital for identifying any unique component of human speech and language.
AnikinA.PerssonT. (2017). Nonlinguistic vocalizations from online amateur videos for emotion research: A validated corpus. Behavior Research Methods, 49, 758–771.
2.
ArbibM. A. (2005). From monkey-like action recognition to human language: An evolutionary framework for neurolinguistics. Behavioral & Brain Sciences, 28, 105–124.
3.
BehrO.von HelversenO. (2004). Bat serenades—Complex courtship songs of the sac-winged bat (Saccopteryx bilineata). Behavioral Ecology and Sociobiology, 56, 106–115.
4.
BerwickR. C.ChomskyN. (2016). Why only us: Language and evolution. Cambridge, MA: MIT Press.
5.
BerwickR. C.FriedericiA. D.ChomskyN.BolhuisJ. J. (2013). Evolution, brain, and the nature of language. Trends in Cognitive Sciences, 17, 89–98.
6.
BerwickR. C.OkanoyaK.BeckersG. J. L.BolhuisJ. J. (2011). Songs to syntax: The linguistics of birdsong. Trends in Cognitive Sciences, 15, 113–121.
7.
BloomfieldT.GentnerT.MargoliashD. (2011). What birds have to say about language. Nature Neuroscience, 14, 947–948.
8.
BohnK. M.Schmidt-FrenchB.MaS. T.PollakG. D. (2008). Syllable acoustics, temporal patterns, and call composition vary with behavioral context in Mexican free-tailed bats. The Journal of the Acoustical Society of America, 124, 1838–1848.
9.
BoinskiS. (1993). Vocal coordination of troop movement among white-faced capuchin monkeys, Cebus capucinus. American Journal of Primatology, 30, 85–100.
10.
BolhuisJ. J.TattersallI.ChomskyN.BerwickR. C. (2014). How could language have evolved?PLOS Biology, 12(8), Article e1001934. doi:10.1371/journal.pbio.1001934
11.
BrainardM. S.DoupeA. J. (2002). What songbirds teach us about learning. Nature, 417, 351–358.
12.
CaineN. G.AddingtonR. L.WindfelderT. L. (1995). Factors affecting the rates of food calls given by red-bellied tamarins. Animal Behaviour, 50, 53–60.
13.
CorballisM. C. (2002). From hand to mouth: The gestural origins of language. In KirbyM. H. C. S. (Ed.), Language evolution (pp. 201–218). New York, NY: Oxford University Press.
14.
CorballisM. C. (2016). The evolution of language: Sharing our mental lives. Journal of Neurolinguistics, 43, 120–132.
15.
CrockfordC.BoeschC. (2003). Context-specific calls in wild chimpanzees, Pan troglodytes verus: Analysis of barks. Animal Behaviour, 66, 115–125.
16.
CrockfordC.GruberT.ZuberbühlerK. (2018). Chimpanzee quiet hoo variants differ according to context. Royal Society Open Science, 5(5), Article 172066. doi:10.1098/rsos.172066
17.
Du BoisJ. W.EnglebretsonR. (2005). Santa Barbara corpus of spoken American English, Part 4. Philadelphia, PA: Linguistic Data Consortium.
18.
DunbarR. I. M. (2017). Group size, vocal grooming and the origins of language. Psychonomic Bulletin & Review, 24, 209–212.
19.
ElieJ. E.TheunissenF. E. (2015a). Meaning in the avian auditory cortex: Neural representation of communication calls. European Journal of Neuroscience, 41, 546–567.
20.
ElieJ. E.TheunissenF. E. (2015b). The vocal repertoire of the domesticated zebra finch: A data-driven approach to decipher the information-bearing acoustic features of communication signals. Animal Cognition, 19, 285–315.
21.
EvansC. S.EvansL.MarlerP. (1993). On the meaning of alarm calls: Functional reference in an avian vocal system. Animal Behaviour, 46, 23–38.
22.
EvansC. S.MarlerP. (1994). Food calling and audience effects in male chickens, Gallus gallus: Their relationships to food availability, courtship and social facilitation. Animal Behaviour, 47, 1159–1170.
23.
FedurekP.SlocombeK. E.ZuberbühlerK. (2015). Chimpanzees communicate to two different audiences during aggressive interactions. Animal Behaviour, 110, 21–28.
24.
FitchW. T. (2000). The evolution of speech: A comparative review. Trends in Cognitive Sciences, 4, 258–267.
25.
FitchW. T. (2017). Empirical approaches to the study of language evolution. Psychonomic Bulletin & Review, 24, 3–33.
26.
GarlandE. C.GoldizenA. W.RekdahlM. L.ConstantineR.GarrigueC.HauserN. D.. . . NoadM. J. (2011). Dynamic horizontal cultural transmission of humpback whale song at the ocean basin scale. Current Biology, 21, 687–691.
27.
GlassJ. (2012). Towards unsupervised speech processing. In 11th International Conference on Information Science, Signal Processing and their Applications (ISSPA). doi:10.1109/ISSPA.2012.6310546
28.
GouzoulesS.GouzoulesH.MarlerP. (1984). Rhesus monkey (Macaca mulatta) screams: Representational signalling in the recruitment of agonistic aid. Animal Behaviour, 32, 182–193.
29.
HauserM. D.ChomskyN.FitchW. T. (2002). The faculty of language: What is it, who has it, and how did it evolve?Science, 298, 1569–1579.
30.
HayesC. (1951). The ape in our house. Oxford, England: Harper.
31.
HewesG. W.AndrewR. J.CariniL.ChoeH.GardnerR. A.KortlandtA.. . . WescottR. W. (1973). Primate communication and the gestural origin of language [and comments and reply]. Current Anthropology, 14, 5–24.
32.
JanikV. M.SlaterP. J. (1998). Context-specific use suggests that bottlenose dolphin signature whistles are cohesion calls. Animal Behaviour, 56, 829–838.
33.
KingS. L.JanikV. M. (2015). Come dine with me: Food-associated social signalling in wild bottlenose dolphins (Tursiops truncatus). Animal Cognition, 18, 969–974.
34.
KnörnschildM.FeifelM.KalkoE. K. V. (2013). Mother–offspring recognition in the bat Carollia perspicillata. Animal Behaviour, 86, 941–948.
35.
KnörnschildM.NagyM.MetzM.MayerF.von HelversenO. (2009). Complex vocal imitation during ontogeny in a bat. Biology Letters, 6, 156–159.
36.
LipkindD.MarcusG. F.BemisD. K.SasaharaK.JacobyN.TakahasiM.. . . OkanoyaK. (2013). Stepwise acquisition of vocal combinatorial capacity in songbirds and human infants. Nature, 498, 104–108.
37.
ManserM. B.SeyfarthR. M.CheneyD. L. (2002). Suricate alarm calls signal predator class and urgency. Trends in Cognitive Sciences, 6, 55–57.
38.
MarlerP. (2004). Bird calls: Their potential for behavioral neurobiology. Annals of the New York Academy of Sciences, 1016, 31–44.
39.
MercierS.NeumannC.van de WaalE.CholletE.MericdeBellefonJ.ZuberbühlerK. (2017). Vervet monkeys greet adult males during high-risk situations. Animal Behaviour, 132, 229–245.
40.
MummC. A. S.KnörnschildM. (2014). The vocal repertoire of adult and neonate giant otters (Pteronura brasiliensis). PLOS ONE, 9(11), Article e112562. doi:10.1371/journal.pone.0112562
41.
ParkA. S.GlassJ. R. (2008). Unsupervised pattern discovery in speech. IEEE Transactions on Audio, Speech, and Language Processing, 16, 186–197. doi:10.1109/tasl.2007.909282
42.
PetkovC.JarvisE. (2012). Birds, primates, and spoken language origins: Behavioral phenotypes and neurobiological substrates. Frontiers in Evolutionary Neuroscience, 4, Article 2. doi:10.3389/fnevo.2012.00012
43.
PooleJ. H.TyackP. L.Stoeger-HorwathA. S.WatwoodS. (2005). Animal behaviour: Elephants are capable of vocal learning. Nature, 434, 455–456.
44.
PratY.AzoulayL.DorR.YovelY. (2017). Crowd vocal learning induces vocal dialects in bats: Playback of conspecifics shapes fundamental frequency usage by pups. PLOS Biology, 15(10), Article e2002556. doi:10.1371/journal.pbio.2002556
45.
PratY.TaubM.PrattE.YovelY. (2017). An annotated dataset of Egyptian fruit bat vocalizations across varying contexts and during vocal ontogeny. Scientific Data, 4, Article 170143. doi:10.1038/sdata.2017.143
46.
PratY.TaubM.YovelY. (2015). Vocal learning in a social mammal: Demonstrated by isolation and playback experiments in bats. Science Advances, 1(2), Article e1500019. doi:10.1126/sciadv.1500019
47.
PratY.TaubM.YovelY. (2016). Everyday bat vocalizations contain information about emitter, addressee, context, and behavior. Scientific Reports, 6, Article 39419.
48.
RendellL.WhiteheadH. (2001). Culture in whales and dolphins. Behavioral & Brain Sciences, 24, 309–324. doi:10.1038/srep39419
49.
SalmiR.HammerschmidtK.Doran-SheehyD. M. (2013). Western gorilla vocal repertoire and contextual Use of vocalizations. Ethology, 119, 831–847.
50.
ScharffC.PetriJ. (2011). Evo-devo, deep homology and FoxP2: Implications for the evolution of speech and language. Philosophical Transactions of the Royal Society B: Biological Sciences, 366, 2124–2140.
51.
SchelA. M.TownsendS. W.MachandaZ.ZuberbühlerK.SlocombeK. E. (2013). Chimpanzee alarm call production meets key criteria for intentionality. PLOS ONE, 8(10), e76674. doi:10.1371/journal.pone.0076674
52.
SeyfarthR. M.CheneyD. L. (2003). Meaning and emotion in animal vocalizations. Annals of the New York Academy of Sciences, 1000, 32–55.
53.
SeyfarthR. M.CheneyD. L.MarlerP. (1980). Vervet monkey alarm calls: Semantic communication in a free-ranging primate. Animal Behaviour, 28, 1070–1094.
54.
SlocombeK. E.KallerT.CallJ.ZuberbühlerK. (2010). Chimpanzees extract social information from agonistic screams. PLOS ONE, 5(7), Article e11473. doi.org/10.1371/journal.pone.0011473
55.
SlocombeK. E.ZuberbühlerK. (2005). Functionally referential communication in a chimpanzee. Current Biology: CB, 15, 1779–1784.
56.
SlocombeK. E.ZuberbühlerK. (2006). Food-associated calls in chimpanzees: Responses to food types or food preferences?Animal Behaviour, 72, 989–999.
57.
StoegerA. S.MietchenD.OhS.De SilvaS.HerbstC. T.KwonS.FitchW. T. (2012). An Asian elephant imitates human speech. Current Biology, 22, 2144–2148.
58.
TchernichovskiO.MitraP. P.LintsT.NottebohmF. (2001). Dynamics of the vocal imitation process: How a zebra finch learns its song. Science, 291, 2564–2569.
59.
ten CateC.OkanoyaK. (2012). Revisiting the syntactic abilities of non-human animals: Natural vocalizations and artificial grammar learning. Philosophical Transactions of the Royal Society B: Biological Sciences, 367, 1984–1994.
60.
ThorpeW. H. (1958). The learning of song patterns by birds, with especial reference to the song of the chaffinchFringilla coelebs. IBIS, 100, 535–570.
61.
TomaselloM. (2008). Origins of human communication. Cambridge, MA: MIT Press.
62.
TownsendS. W.ManserM. B. (2013). Functionally referential communication in mammals: The past, present and the future. Ethology, 119, 1–11.
63.
TyackP. (1981). Interactions between singing Hawaiian humpback whales and conspecifics nearby. Behavioral Ecology and Sociobiology, 8, 105–116.
64.
VersteeghM.AngueraX.JansenA.DupouxE. (2016). The zero resource speech challenge 2015: Proposed approaches and results. Procedia Computer Science, 81, 67–72.
65.
VitaleA.ZanzoniM.QueyrasA.ChiarottiF. (2003). Degree of social contact affects the emission of food calls in the common marmoset (Callithrix jacchus). American Journal of Primatology, 59, 21–28.
66.
WheelerB. C.FischerJ. (2012). Functionally referential signals: A promising paradigm whose time has passed. Evolutionary Anthropology, 21, 195–205.
67.
WilkinsonG. S.BoughmanJ. W. (1998). Social calls coordinate foraging in greater spear-nosed bats. Animal Behaviour, 55, 337–350.
68.
ZuberbühlerK. (2001). Predator-specific alarm calls in Campbell’s monkeys, Cercopithecus campbelli. Behavioral Ecology and Sociobiology, 50, 414–422.
69.
ZuberbühlerK.CheneyD. L.SeyfarthR. M. (1999). Conceptual semantics in a nonhuman primate. Journal of Comparative Psychology, 113, 33–42.
