The evolution of early human language
Here I review my work on the evolution of early human language.
Selective scenarios for the emergence of natural language
Számadó, S., & Szathmáry, E.
In this paper we set out to clarify how evolutionary scenarios for the origin of human language should be evaluated. Rather than proposing an additional adaptive story, our aim is to articulate a set of theoretical constraints—derived from signalling theory, evolutionary game theory, and the framework of major evolutionary transitions—that any credible account must respect. We argue that language should be understood as a selection-limited transition: most of the cognitive and genetic prerequisites were already present in great apes, but only a particular socio-ecological niche in the human lineage generated the selective conditions that favoured the emergence of fully fledged linguistic communication.
A central theme of our analysis is the problem of signal honesty. Human language is a predominantly low-cost signalling system: linguistic signals are easy to produce, yet they remain reliable enough to support cooperative behaviours of great complexity. Drawing on formal models, we emphasize that low-cost honest signalling can only remain evolutionarily stable when there is high overlap of interests between speakers and listeners, or when messages are verifiable and cheaters subject to detection and punishment. Accordingly, any proposed evolutionary scenario must address how honesty could have been maintained in the face of potential conflicts of interest.
We use these constraints to examine prominent hypotheses about language origins—such as grooming, gossip, mating contracts, cooperative hunting, tool-making, ritual, and mother–infant communication. Scenarios grounded in substantial shared interests, such as cooperative foraging or technological coordination, more readily satisfy the requirements for the stability of honest cheap talk. By contrast, scenarios centred on domains with high conflict of interest and limited verifiability, such as gossip or sexual bargaining, face greater theoretical challenges if presented as primary drivers of linguistic evolution.
Finally, we place the emergence of language within the broader context of major evolutionary transitions. We interpret language as a new inheritance and coordination system that enables cumulative cultural evolution and large-scale cooperation. While acknowledging the genetic underpinnings of linguistic capacity, we stress that no single “language gene” is likely to account for its emergence; instead, modest genetic changes combined with strong selection in a unique socio-ecological environment produced the transition. Our core contribution is thus methodological: we offer a principled framework grounded in evolutionary theory for assessing which scenarios of language evolution are plausible and which fail to satisfy fundamental constraints.
Számadó, S., & Szathmáry, E. (2006). Selective scenarios for the emergence of natural language. Trends in Ecology & Evolution, 21(10), 555-561.
Pre-hunt communication provides context for the evolution of early human language.
Számadó, S.
In this article I develop the hypothesis that pre-hunt communication in early hominins provided the initial ecological and social context for the evolution of human language. I start from the observation that big-game hunting would have generated a strong shared interest among group members in coordinating their actions, and that such coordination requires individuals to exchange information about prey, location, timing, and roles. I argue that this setting solves a key problem in language evolution: how a cheap, flexible signalling system could remain sufficiently honest and useful to be favoured by natural selection. In pre-hunt contexts, interests are largely aligned (everyone benefits if the hunt succeeds), and much of the content is verifiable (a hunt either results in meat or not), which makes honest communication evolutionarily stable.
I propose that this “first step” in language evolution unfolded in two stages. In the first stage, hominins used primarily indexical and iconic signs to recruit others for the hunt—for example, gestures or vocalisations that directly pointed to prey or imitated their behaviour and the intended actions. In the second stage, as hunts became more complex and group size increased, division of labour evolved. Thus, there was an escalating selective pressure for richer pre-hunt planning: signals had to encode not only “there is prey” but also who should do what, when, and where. This drove an increase in combinatorial and structural complexity of the communicative system, laying foundations for more language-like organisation.
To support this scenario, I review archaeological, palaeoecological, and comparative data on early hominin meat-eating, hunting, and scavenging. I argue that the evidence is more consistent with an active hunting niche than with “power/confrontational scavenging” as the main source of meat: confrontational scavenging is highly dangerous, poorly supported by primate behaviour (e.g. chimpanzees rarely engage in such behaviour), and ecologically implausible as a primary strategy without prior hunting skill. Active hunting, by contrast, fits better with known chimpanzee behaviour and with the faunal and taphonomic record, making it a more realistic context in which complex pre-hunt communication would be favoured.
Finally, I argue that cultural transmission of hunting know-how and tool use helps explain why this transition was unique to humans. Once pre-hunt communication began to support the sharing and refinement of hunting techniques, it created a feedback loop between improved tools, more efficient hunting, and increasing communicative sophistication. This loop, I suggest, marks the earliest phase of the trajectory that eventually produced fully fledged human language: not a general-purpose “language for everything” from the start, but a system that first evolved to organize and coordinate cooperative big-game hunting, and only later expanded to the wide range of functions we observe today.
Számadó, S. (2010). Pre-hunt communication provides context for the evolution of early human language. Biological theory, 5(4), 366-382.
Language: a social history of words
Szathmáry, E., & Számadó, S.
In this essay we argue that language must be understood as part of a suite of uniquely human traits, rather than as an isolated module or capacity. We begin by noting that some aspects of word learning are not strictly unique—dogs and apes can learn the meanings of many words—but human language is distinctive in its symbolic richness, combinatorial structure and open-ended expressivity. Because language probably evolved in concert with other human specializations, such as advanced tool use, powerful social learning, shared attention, teaching and complex cooperation, we contend that it makes little sense to treat “language” as a self-contained trait. Instead, we propose that the interdependence of these traits calls for an integrated approach to brain function and evolution, rather than a view of the brain as a set of largely independent modules.
We therefore situate language within the broader framework of major evolutionary transitions and gene–culture coevolution. On our view, language is both enabled by specific biological changes (for example in neural circuitry and language-related genes) and, in turn, reshapes selection pressures acting on the brain and on behaviour. We discuss how emerging findings in genetics and neuroscience challenge overly simple pictures of a “language module” or a single “language gene” and instead point to complex developmental and neural networks in which linguistic, social and cognitive capacities are deeply intertwined. This supports the idea that several human traits—language, theory of mind, cooperation, pedagogy, and technological innovation—may have evolved more readily together than one by one, because of synergistic fitness benefits.
A central theme of the essay is that language is not only a communication system but also a powerful engine of cultural evolution. Words and constructions act as cultural replicators that can be transmitted, combined and refined far more quickly than genetic variants. We express this idea by saying that “one word can be worth a thousand genes”: a single culturally transmitted term or concept can encapsulate a great deal of adaptive information—about technology, social norms, or the natural world—and can spread through a population on timescales far shorter than genetic evolution allows. In doing so, language reprograms cognitive development, scaffolds abstract thought, and allows cumulative cultural change in science, law, technology and social institutions.
Finally, we argue that language has been a key driver of human niche construction. Linguistic communication has enabled the creation of highly altered social and physical environments—complex institutions, technical systems and shared symbolic worlds—which then feed back on both cultural and biological evolution. In this sense, language has a “social history of words”: each word carries with it a trajectory shaped by many generations of users, embedded in particular practices and institutions. Our overall message is that to understand what makes humans unique, and how language evolved, we must study words in the context of the broader web of human cognitive, social and cultural evolution, rather than as a stand-alone faculty.
Szathmáry, E., & Számadó, S. (2008). Language: a social history of words. Nature, 456(7218), 40-41.
What are the possible biological and genetic foundations for syntactic phenomena?
Számadó Szabolcs, Hurford James R., Bishop Dorothy V. M., Deacon Terrence W., d’Errico Francesco, Fischer Julia, Okanoya Kazuo, Szathmáry Eörs, White Stephanie A.
In this chapter we set out to ask what biology and genetics can really tell us about syntax—understood as the combinatorial, hierarchical aspect of language that appears uniquely human. We begin by arguing that the usual comparative method in biology, though insufficient on its own to explain human syntax, is still indispensable for a “bottom-up” approach: by charting what animals can and cannot do, and how their brains and genomes differ from ours, we can narrow down plausible evolutionary pathways for syntactic abilities.
We first review “syntax in animals?” in a deliberately skeptical way. We contrast general features of animal communication with human language and stress that even impressive complexity in animal vocal sequences (for example, rich phonological or sequencing patterns) does not automatically amount to lexical or phrase-structure syntax in the human sense. We examine experimental work on the grammatical capacities of nonhuman species and draw on neurobiological studies in humans to show that the circuitry implicated in syntactic processing appears to be both specialized and distributed in ways not yet matched in other species. Our conclusion is that animal studies can reveal precursors and constraints, but so far, they do not demonstrate anything like full human-style syntax.
Next, we turn to genetic influences on syntax. Here we synthesize evidence from heritability studies and from specific language impairments to argue that syntactic ability has a substantial genetic component, but almost certainly no single “syntax gene.” Instead, we suggest a polygenic architecture, with genes affecting neural development, connectivity, and learning biases that in turn support syntactic competence. We discuss well-known candidates from the language-genetics literature (such as FOXP2) not as a complete explanation, but as illustrative cases showing how mutations can affect aspects of morphosyntax, articulation, and sequencing, thereby constraining theories that postulate a purely abstract, gene-free syntax faculty.
Building on this, we ask how an evolutionary perspective constrains syntactic theory. Any theory of syntax must, in our view, be at least biologically possible: it must be compatible with incremental change, with known limits of neural and genetic systems, and with the comparative evidence. Highly baroque or non-incremental theories of grammar, which posit radically discontinuous changes or hyper-minimal innate blueprints, are difficult to reconcile with what we know about evolution and development. We therefore sketch evolutionary mechanisms that could plausibly underwrite the rise of syntax from nonlinguistic capacities: exaptation of pre-existing cognitive and motor systems; and several forms of gene–culture coevolution, including Baldwinian processes (where learning biases become genetically supported), Waddingtonian genetic assimilation (where formerly plastic responses become canalized), and niche construction (where culturally created environments feed back on selection pressures for syntactic abilities).
Finally, we ask what the fossil and archaeological record can reasonably tell us about syntax. We review cranial and endocast evidence, changes in vocal tract morphology, and, most importantly, the appearance of complex tools, symbolic artifacts, and social technologies that would plausibly require—or at least strongly favour—some form of syntactic communication. These data do not “prove” when syntax emerged, but they allow us to formulate testable predictions about its timing and about accompanying changes in brain and behaviour. We close by emphasizing that no single line of evidence—animal behaviour, genes, brains, or fossils—can by itself answer the question we pose. What we offer instead is a biologically grounded framework: a set of constraints and mechanisms within which any serious theory of the origins and structure of syntax must fit.
Számadó Szabolcs, Hurford James R., Bishop Dorothy V. M., Deacon Terrence W., d’Errico Francesco, Fischer Julia, Okanoya Kazuo, Szathmáry Eörs, White Stephanie A. (2009) What are the possible biological and genetic foundations for syntactic phenomena? in: Biological Foundations and Origin of Syntax, Derek Bickerton (ed.), Eörs Szathmáry (ed.), 207–236.
Evolutionary biological foundations of the origin of language: the co‐evolution of language and brain
Szabolcs Számadó & Eörs Szathmáry
In this chapter we ask how biological evolution of the brain and the cultural evolution of language interacted, and what this co-evolution implies for theories of language origins. We start from a general evolutionary question: how can organisms adapt to moving targets—as when a crucial part of the environment (here, conspecific communication) is itself changing rapidly? We distinguish three main adaptive routes: (i) ordinary genetic evolution acting on heritable variation; (ii) phenotypic plasticity, where the same genotype yields different phenotypes depending on experience; and (iii) the evolution of specialized organs or systems whose function is precisely to track fast-changing aspects of the environment. We argue that human language and the language-ready brain arose through the combined action of all three mechanisms.
We then develop the idea of co-evolution between language and brain, an idea that goes back at least to Darwin and has been revived in modern work on gene–culture coevolution. On our view, emerging linguistic practices—however primitive initially—altered the selective environment for hominin brains: individuals better able to learn, process, and use these signals gained fitness advantages. In turn, genetic changes in neural development and connectivity made more sophisticated linguistic systems learnable and usable, driving a spiral of mutual reinforcement between cultural change in language and biological change in the brain.
To make this picture biologically concrete, we review evidence from comparative neuroanatomy, behavioural studies, fossils, and genetics. We note that the human brain, and especially regions implicated in language (such as frontal and temporal areas), shows signs of both quantitative and qualitative change relative to other primates, including possible episodes of accelerated evolution in nervous-system genes. At the same time, twin and imaging studies indicate significant genetic control over large-scale brain anatomy, including regions associated with language, which constrains purely “free-floating” cultural accounts of language evolution. We suggest that even early Homo (e.g. H. erectus) likely possessed communication systems more complex than those of extant apes, giving natural selection substantial time to tune brain organization to the demands of increasingly language-like communication.
A key theme of the chapter is that phenotypic plasticity and learning are not alternatives to evolution, but part of the evolutionary process. We draw on concepts such as the Baldwin effect and genetic assimilation: learned, plastic responses to a culturally structured linguistic environment can become partially stabilized in the genotype when they are consistently advantageous. In this way, biases that favour efficient language learning (for example, certain perceptual or combinatorial tendencies) may first arise as flexible learning strategies and later become canalized as aspects of brain organization. This helps explain how language can both be highly learned and yet depend on substantial biological specialization.
We conclude that any serious account of the origin of language must treat it as the outcome of interacting biological and cultural dynamics, not as a purely genetic “language module” nor as a purely cultural invention riding on an unchanged primate brain. The human brain is, we argue, a specialized organ for tracking fast-changing, linguistically structured social environments; language, in turn, is shaped by what such a brain can learn and process. Our main contribution is to offer an explicitly evolutionary framework—built around moving targets, plasticity, and specialized organs—for understanding how the co-evolution of language and brain could have produced the modern human language faculty.
Szabolcs Számadó, Eörs Szathmáry (2012) Evolutionary biological foundations of the origin of language: the co‐evolution of language and brain. in: The Oxford Handbook of Language Evolution, Kathleen R. Gibson (ed.), Maggie Tallerman (ed.), 157–167.