The Social Brain Is Not Enough: On the Importance of the Ecological Brain for the Origin of Language

The prefrontal cortex: from monkey to man

The prefrontal cortex is so important to human beings that, if deprived of it, our behaviour is reduced to action-reactions and automatisms, with no ability to make deliberate decisions. Why does the prefrontal cortex hold such importance in humans? In answer, this review draws on the proximity between humans and other primates, which enables us, through comparative anatomical-functional analysis, to understand the cognitive functions we have in common and specify those that distinguish humans from their closest cousins. First, a focus on the lateral region of the prefrontal cortex illustrates the existence of a continuum between rhesus monkeys (the most studied primates in neuroscience) and humans for most of the major cognitive functions in which this region of the brain plays a central role. This continuum involves the presence of elementary mental operations in the rhesus monkey (e.g. working memory or response inhibition) that are constitutive of 'macro-functions' such as planning, problem-solving and even language production. Second, the human prefrontal cortex has developed dramatically compared to that of other primates. This increase seems to concern the most anterior part (the frontopolar cortex). In humans, the development of the most anterior prefrontal cortex is associated with three major and interrelated cognitive changes: (i) a greater working memory capacity, allowing for greater integration of past experiences and prospective futures; (ii) a greater capacity to link discontinuous or distant data, whether temporal or semantic; and (iii) a greater capacity for abstraction, allowing humans to classify knowledge in different ways, to engage in analogical reasoning or to acquire abstract values that give rise to our beliefs and morals. Together, these new skills enable us, among other things, to develop highly sophisticated social interactions based on language, enabling us to conceive beliefs and moral judgements and to conceptualize, create and extend our vision of our environment beyond what we can physically grasp. Finally, a model of the transition of prefrontal functions between humans and non-human primates concludes this review.

Human Self-Domestication and the Evolution of Pragmatics

As proposed for the emergence of modern languages, we argue that modern uses of languages (pragmatics) also evolved gradually in our species under the effects of human self-domestication, with three key aspects involved in a complex feedback loop: (a) a reduction in reactive aggression, (b) the sophistication of language structure (with emerging grammars initially facilitating the transition from physical aggression to verbal aggression); and (c) the potentiation of pragmatic principles governing conversation, including, but not limited to, turn-taking and inferential abilities. Our core hypothesis is that the reduction in reactive aggression, one of the key factors in self-domestication processes, enabled us to fully exploit our cognitive and interactional potential as applied to linguistic exchanges, and ultimately to evolve a specific form of communication governed by persuasive reciprocity-a trait of human conversation characterized by both competition and cooperation. In turn, both early crude forms of language, well suited for verbal aggression/insult, and later more sophisticated forms of language, well suited for persuasive reciprocity, significantly contributed to the resolution and reduction of (physical) aggression, thus having a return effect on the self-domestication processes. Supporting evidence for our proposal, as well as grounds for further testing, comes mainly from the consideration of cognitive disorders, which typically simultaneously present abnormal features of self-domestication (including aggressive behavior) and problems with pragmatics and social functioning. While various approaches to language evolution typically reduce it to a single factor, our approach considers language evolution as a multifactorial process, with each player acting upon the other, engaging in an intense mutually reinforcing feedback loop. Moreover, we see language evolution as a gradual process, continuous with the pre-linguistic cognitive abilities, which were engaged in a positive feedback loop with linguistic innovations, and where gene-culture co-evolution and cultural niche construction were the main driving forces.

Persuasive conversation as a new form of communication in Homo sapiens

The aim of this paper is twofold: to propose that conversation is the distinctive feature of Homo sapiens' communication; and to show that the emergence of modern language is tied to the transition from pantomime to verbal and grammatically complex forms of narrative. It is suggested that (animal and human) communication is a form of persuasion and that storytelling was the best tool developed by humans to convince others. In the early stage of communication, archaic hominins used forms of pantomimic storytelling to persuade others. Although pantomime is a powerful tool for persuasive communication, it is proposed that it is not an effective tool for persuasive conversation: conversation is characterized by a form of reciprocal persuasion among peers; instead, pantomime has a mainly asymmetrical character. The selective pressure towards persuasive reciprocity of the conversational level is the evolutionary reason that allowed the transition from pantomime to grammatically complex codes in H. sapiens, which favoured the evolution of speech. This article is part of the theme issue 'Reconstructing prehistoric languages'.

Time and Narrative: An Investigation of Storytelling Abilities in Children With Autism Spectrum Disorder

This study analyzed the relation between mental time travel (MTT) and the ability to produce a storytelling focusing on global coherence, which is one of the most notable characteristics of narrative discourse. As global coherence is strictly tied to the temporal sequence of the events narrated in a story, we hypothesized that the construction of coherent narratives would rely on the ability to mentally navigate in time. To test such a hypothesis, we investigated the relation between one component of MTT—namely, episodic future thinking (EFT)—and narrative production skills by comparing the narratives uttered by 66 children with high-functioning autism spectrum disorder (ASD) with those produced by 66 children with typical development. EFT was assessed by administering a task with minimal narrative demands, whereas storytelling production skills were assessed by administering two narrative production tasks that required children to generate future or past episodes with respect to the target stimuli. The results showed that EFT skills were impaired only in a subgroup of children with ASD and that such subgroup performed significantly worse on the narrative production task than ASD participants with high EFT skills and participants with typical development. The practical and theoretical implications of these findings are discussed.

Life Themes and Interpersonal Motivational Systems in the Narrative Self-construction

What makes unique and unrepeatable individuals is their ability to write their own story attributing meaning, sharing it through narration, giving coherence to the information related to the interpersonal motivational systems, and creating alternative hierarchies to those biologically provided by the genetic code. Through clinical narratives and narrative literature, we can observe the recurrence of specific topics, across time and different cultures. Hence, we wondered whether there are some evolutionary suggestions that guide us in the construction of the narrative-autobiographical contents. In this article we proposed a theoretical-clinical hypothesis about the existence of a biological disposition to identify as fundamental six Life Themes (LTs) that contribute to defining the image of the self and the world: Love, Personal Value, Power, Justice, Truth, and Freedom. Besides the innumerable narratives dependent upon context, there may be many ways of telling stories that, instead, would be reported to these few essential themes. A narrative review of the literature about these concepts follows the systematic explanation of the perspective about the LTs as attractors of meaning. The manuscript considers also the process of co-construction of meanings within the interpersonal relationships and the influences of these on the narratives. In particular, we focused on the importance of episodic and autobiographical memory related to the attachment and significant figures, in the construction of the personal story and the LTs. We also explained the possible clinical implications of the theoretical hypothesis of LTs. Within clinical conversations, the LTs could be expressed rigidly or, otherwise, in a confused way. The lack of narrative integration may lead to the dominance of chaos or rigidity that generates suffering. A better comprehension of the LTs in patients’ narrations could be useful to identify a narrative profile about the areas of greatest suffering related to the idea of self and the world, as well as to construct an adequate care plan.