 Self-domestication refers to a recent hypothesis about how our species emerged. It claims that the human distinctiveness is, to a large extent, the outcome of an evolutionary process similar to animal domestication. This includes our enhanced social cognition, increased cooperation, and extended social networks, and ultimately, our advanced technology and sophisticated culture. Language is perhaps the most distinctive of human features. In this talk, I will present a model of language evolution under the effects of self-domestication forces. At the basis of this model one can find the idea that self-domestication, through its impact on our behavior, facilitated the creation of the cultural niche that enables the sophistication of language structure and use via a cultural mechanism. Some cognitive changes to which self-domestication might have also aided, like our increased cognitive fluidity, could have also contributed to make human language and human pragmatics more complex. This evolutionary model ties different stages in the evolution of languages with changes in the management of aggression (at the core of the self-domestication hypothesis), with both aspects being engaged in a mutually reinforcing feedback loop, as both depend on, and impact on a common neurobiological substrate. The model argues for a strong continuity between human language and the cognitive abilities and behaviors of other species, but it also grants cultural evolution a crucial role in language evolution.

The evolution of language under self-domestication forces: a model

**Author(s):** Theofanopoulou, C. It has been long thought that the kind of social interaction modern humans display should have been a key feature in the evolution of language (Tomasello et al., 2003). At the same time, our increased prosociality has independently been hypothesized to be very similar to the one we witness in domesticated species (e.g., Thomas, 2014). In this talk, I will connect the dots between several studies I have run in the past years around the topic of human self-domestication and its relevance to speech evolution. I will present genomic evidence suggesting that modern humans provide a good case for self-domestication, based on the significant convergence in signs of positive selection found in the genomes of domesticated species and modern humans (Theofanopoulou et al. 2017). I will show evidence supporting that the oxytocin-vasotocin system is a good candidate for the neurobiology underlying the vocal complexity differences we observe in domesticated vs. wild avian species (Tobari, Theofanopoulou et al. 2021), and propose how these findings can shed light on the evolution of human speech. Lastly, I will present modern human specific alleles we identified in the oxytocin and vasotocin receptors, when compared to archaic humans and non-human primates (Theofanopoulou et al. 2022) and will explain how these sites could have impacted the evolution of human prosociality via self-domestication.

Human self-domestication and speech evolution through the lens of the oxytocin and vasotocin gene family

Words in human languages cluster together in phonological neighborhoods more closely than would be expected by chance. But why? One explanation is that large neighborhoods are directly selected for, possibly because they scaffold word learning and production. But it's also possible that they emerge as a byproduct of other constraints or selection pressures operating over real lexica. We advance one such selection pressure as a candidate explanation. A pressure to avoid overloading unique wordforms with homophones may lead to clusters of words that are not identical but similar. Using simulated baselines, we test the viability of this alternative account. We find that a pressure against loading too many meanings on unique wordforms––paired with the phonotactics of a target language––produces lexica with neighborhoods that are at least as large on average as those in real lexica. This does not rule out the possibility of a pro-neighborhood pressure, but it does demonstrate the viability of a parsimonious alternative account based on a pressure against homonymy for which there is independent evidence.

Can a pressure against homophones explain phonological neighborhoods?

As efficient systems of communication, languages are usually expected to map meanings to forms in a one-to-one way, using for example the same affix form (e.g., -s in English) every time a particular meaning is intended (e.g., plural number), and placing affixes with the same meaning consistently in the same position (e.g., always suffixal). Forms and positional rules extending over contexts with a common meaning (e.g., plural in 1PL, 2PL, 3PL) are thus considered natural, and those extending over contexts with no consistent common meaning (e.g., 1PL and 3SG) are considered unnatural. Natural patterns are most common cross-linguistically, and most learnable in experiments; however, little is yet know about differences between unnatural classes. In this study we explore syncretism (i.e., use of the same form in different functions) and affix position in the domain of person and number agreement in verbs, both cross-linguistically and in artificial language learning experiments. Results from the two approaches and both phenomena converge in finding a gradient of (un)naturalness. Rather than a dichotomous natural/unnatural distinction, we found that both cross-linguistic frequency and learnability are proportional to the amount of shared feature values among the contexts requiring the same form or position. We argue that a cognitive bias towards similarity-based structure explains our experimental results and could be driving the patterns observed in natural languages.

A Naturalness Gradient Shapes the Learnability and Cross-Linguistic Distribution of Morphological Paradigms

Typological data shows a tendency for languages to exhibit harmonic (i.e. consistent) ordering between heads and dependents. However, some categories seem to contradict this tendency. Here we investigate one such case, the order of the noun with respect to two dependents—adjectives, which tend to follow the noun and genitives which precede. We report two silent gesture experiments examining (i) whether there are cognitive biases favouring postnominal adjective and prenominal genitive order in a single trial judgement task, and (ii) if those preferences continue to influence order when participants learn a complete word order system. Our results shed light on how biases for individual categories of elements interact with biases that affect the wider linguistic system. While participants strongly prefer postnominal adjectives and prenominal genitives when these are judged in isolation, when they learn a system of ordering, these biases are obscured and (at least in some cases) harmony emerges.

The Influence of Category-specific and System-wide Preferences on Cross-Linguistic Word Order Patterns

Recent experimental and computational modelling work has found that languages are shaped by the referential context in which they operate. Wray and Grace (2007) argue that even compositionality, traditionally regarded as a universal and fundamental feature of human languages, may have only culturally evolved in response to changing social contexts. But how can the referential contexts of individual interactions come to shape the level of compositionality in the language of an entire community? To explore this question, we propose an iterated hierarchical Bayesian model that shows how partner-specific linguistic innovations can be generalized as community-wide features via a context-sensitive pathway. Our simulations show that the degree of compositionality that evolves in the language of a community depends on the communicative needs of its members, but also on the degree of user uncertainty over the nature of those needs, and on the level of heterogeneity in the community's needs.

The complexity of a language is shaped by the communicative needs of its users and by the hierarchical nature of their social inferences

MIDIA (acronimo di Morfologia dell’Italiano in DIAcronia) è un corpus diacronico bilanciato della lingua italiana che comprende testi che vanno dall’inizio del XIII alla prima metà del XX secolo, per circa 7,5 milioni di occorrenze, liberamente consultabile in rete dal settembre 2014. Realizzato grazie a un finanziamento PRIN del 2009, MIDIA è accessibile all’indirizzo http://www.corpusmidia.unito.it/ e si caratterizza rispetto ad altri corpora in rete per la scansione temporale, la tipologia di testi, la lemmatizzazione. 
Nel nostro intervento vogliamo illustrare (a integrazione e completamento dei contributi raccolti in D’Achille/Grossmann 2017) la concezione e la realizzazione di MIDIA, ma soprattutto fornire alcuni spunti di riflessione riguardanti esempi di impiego di MIDIA per ricerche di tipo morfologico e sintattico. 
Per quanto riguarda la concezione del corpus, parleremo in particolare delle motivazioni che hanno determinato la distinzione in cinque periodi cronologici (1. Dall’inizio del Duecento al 1375; 2. dal 1376 al 1532; 3. dal 1533 al 1691; 4. dal 1692 al 1840; 5. dal 1841 al 1947), scanditi da fatti di storia linguistica, letteraria e culturale che possono essere considerati come punti di svolta nella storia della lingua italiana, e in sette generi testuali (1. testi espositivi; 2. testi giuridico-amministrativi; 3. testi personali; 4. poesia; 5. prosa letteraria; 6. testi scientifici; 7. teatro, oratoria, mimesi dialogica). 
Per quanto riguarda la realizzazione, ci soffermeremo sulla scelta dei criteri di annotazione e di lemmatizzazione richiesti da un corpus così eterogeneo, e sugli interventi di revisione, che abbiano considerato utili al fine di un migliore utilizzo e interrogazione del corpus. 
Forniremo infine alcuni esempi degli impieghi di MIDIA, che, concepito per studi di morfologia derivazionale in prospettiva diacronica (ancora privi di un testo di riferimento paragonabile a Grossmann/Rainer 2004), può essere anche fruito per lo studio della morfologia flessiva, del
lessico e delle costruzioni. 
La lemmatizzazione e l’indicazione delle parti del discorso si basano sul programma Tree-Tagger. Per poter fornire una analisi automatica quanto più possibile adeguata alle variazioni dipendenti dai diversi generi linguistici e dall’estensione temporale dei testi presenti nel corpus, è stato necessario predisporre un file di parametri che modifica e integra con più di 200.000 forme annotate quello realizzato da Marco Baroni per la lingua italiana contemporanea (https://docs.sslmit.unibo.it/doku.php?id=resources:morph-it). 
Oltre all’aggiunta di forme, la revisione del file di parametri ha determinato una ridefinizione dei criteri di lemmatizzazione (che tiene conto della ricca polimorfia caratteristica della storia della lingua italiana) e una parziale modifica (rispetto a quella del file di partenza) della lista delle parti del discorso utilizzate in MIDIA. I risultati automatici del PoS tagging sono stati analizzati in fase di post-elaborazione, e gli errori più frequenti di assegnazione di parte del discorso o di lemmatizzazione sono stati corretti attraverso una procedura manuale mirata. 
L’utilizzo del corpus ha evidenziato la necessità di alcune piccole modifiche nel sistema di interrogazione e nella sua presentazione, come pure dell’aggiunta di alcuni testi al fine di ottenere un migliore bilanciamento del corpus, e anche della correzione di alcuni errori materiali. Le possibilità offerte da MIDIA saranno messe in luce grazie all’illustrazione dei risultati di due ricerche che abbiamo condotto specificamente per quest’occasione: una di carattere propriamente morfologico e una di tipo sintattico. Per la morfologia derivativa, analizzeremo la concorrenza tra i diversi prefissi privativi; per la sintassi la diffusione e lo sviluppo della perifrasi stare + gerundio in rapporto a varie altre perifrasi (tra cui in particolare stare a + infinito e stare per + infinito).

Riferimenti bibliografici / References 

D’Achille, Paolo / Grossmann, Maria (a cura di). 2017. Per la storia della formazione delle parole in italiano: un nuovo corpus in rete (MIDIA) e nuove prospettive di studio. Firenze: Franco Cesati.
Grossmann, Maria / Rainer, Franz (a cura di). 2004. La formazione delle parole in italiano. Tübingen: Niemeyer.

Il corpus MIDIA: concezione, realizzazione, impieghi

Collective ritual is virtually omnipresent across past and present human cultures, and analogous behaviors were documented in non-human primates. However, surprisingly little is known about the evolution of ritual in the hominin lineage as well as their underlying neurocognitive mechanisms. Here, we identify similarity, coalitional, and commitment signals as the essential features of collective ritual and argue that these signals evolved to facilitate mutualistic cooperation. We compare evidence for the communicative function of ritual between contemporary hunter-gatherers and non-human primates and discuss the underlying cognitive mechanisms facilitating these signals. Importantly, we will provide experimental evidence from our lab supporting the role of ritual as a platform for cooperative communication. Synthesizing this evidence, we will suggest that between 500 and 300 ka, collective ritual as a repetitively performed communicative act evolved from rudimentary signaling systems to help facilitate mutualistic cooperation and collective action.

Ritualized commitment displays in humans and non-human primates

This paper explores previous arguments that language 
evolved not from animal communication, as naturally 
assumed by most scholars, but instead out of animal 
cognition. It is proposed here that additional support for this 
argument comes from Cognitive Linguistics, an
interdisciplinary branch of linguistics. Cognitive Linguistics
mediates communication and cognition but, as with Cognitive 
Discourse Analysis, studies language use in terms of what it 
demonstrates about underlying cognitive processes and 
concepts. The paper demonstrates key examples of animal 
cognition’s links to language, with Cognitive Linguistics 
support, as well as the approach’s application to animal 
cognition in terms of domain-general symbolism, beyond 
verbal language. However, because communication remains a 
major function of language, the communicative aspect ought 
to be maintained in the explanation of language evolution.

Cognitive Linguistics Support for the Evolution of Language from Animal Cognition

A fundamental characteristic of human language is its combinatorial nature, which facilitates the communication of infinite meanings (i.e., words) built from finite sounds (i.e., phonemes). Investigating the selective drivers of this combinatorial feature represents a major challenge in the field of language evolution and has prospered into a rich interdisciplinary field. Here, we discuss the emergence of combinatorial structures in (human and non-human) communication systems from an information and coding theoretical perspective. We describe how “noise” (i.e., factors constraining communication processes) can hamper and distort signal transmission and perception, and how such noise-induced impairments can be circumvented through a combinatorial coding scheme that adds redundancy to a signalling system, in turn increasing its robustness and enhancing signal detection and discrimination. In doing so we argue that basic combinatoriality has emerged due to universal constraints imposed on signalling systems, and that human language-like productive combinatoriality builds upon this phenomenon.

Underline digital video library

The evolution of language under self-domestication forces: a model

Human self-domestication and speech evolution through the lens of the oxytocin and vasotocin gene family

Can a pressure against homophones explain phonological neighborhoods?

A Naturalness Gradient Shapes the Learnability and Cross-Linguistic Distribution of Morphological Paradigms

The Influence of Category-specific and System-wide Preferences on Cross-Linguistic Word Order Patterns

The complexity of a language is shaped by the communicative needs of its users and by the hierarchical nature of their social inferences

Il corpus MIDIA: concezione, realizzazione, impieghi

Ritualized commitment displays in humans and non-human primates

Cognitive Linguistics Support for the Evolution of Language from Animal Cognition

An information and coding theoretical approach to combinatorial communication

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