Speech and sexual dimorphism: the history of the issue in the light of modern theories of the origin of speech and experimental data

Semenova Ol'ga Vladimirovna ORCID: 0000-0002-0015-243X Doctor of History Institute of Ethnology and Anthropology(RAS). 117556, Russia, Moscow, Leninsky Prospekt, 32 a, office 1902 m4248296@yandex.ru Other publications by this author

Adam Yuliya Igorevna ORCID: 0000-0003-3839-8360 PhD in History Independent researcher 119334, Russia, Moscow, ul. Leninsky Prospekt, 32 a julia.apalkova@gmail.com

It is no secret that any of our social interactions have a constant speech accompaniment, they are accompanied by endless conversations, exchange of opinions, comments on current events, discussions of the past and the future, and often completely meaningless dialogues and phrases on duty. We really talk a lot, even when it seems to us that not so much has actually been said ^[1]. On average, we pronounce about 16 thousand words per day ^[2]. That's about 1,000 words per hour, or about 16 words per minute — and that's just our everyday spoken language. But if we also take into account listening to conversations, reading, writing, text messages, social networks, television and internal dialogue, it becomes obvious that language and speech completely permeate all aspects of our existence ^{[3; 4]}.

Thus, human speech has two key features: firstly, the constancy of its use and, secondly, its constantly observed lack of content. It is not surprising that these properties of speech formed the basis of the theory of grooming, based on one of the key modern hypotheses of the origin of language in evolutionary biology. Within the framework of this theory, it is assumed that the sound component of grooming interactions played an essential role in the evolution of speech in the human past ^{[5; 6]}. In this sense, people's desire for constant social verbal communication corresponds to the ways of courtship in animals, expressed in the form of regular contact interaction ^[7].  

However, from a bioevolutionary point of view, it would be too wasteful to have such a rich lexical apparatus and sophistication of syntax only for social integration and for maintaining social contacts. In addition, most experts recognize that, first of all, the information component is important in human verbal communication. Thus, proponents of functionalism consider the main communicative function of language. "In short, language is a means of communication. The ability to share thoughts through language provides people with a variety of opportunities for effective interaction that are not available to other biological species" ^{[8, p. 61]}. At the same time, it is noted that our language is not the optimal means for accurate transmission of information ^[9]. After all, a language is a sign system ^[10], and it contains a lot of unnecessary codification: in any language there are elements (they can be phonetic, lexical, morphological, syntactic) that can be replaced by each other within the framework of an utterance without significantly changing the transmitted meaning, there are also means of duplicating information ^[11]. It is also characteristic that our speech contains a lot of idiomatic expressions, metaphors, hyperboles and phrases, often allowing ambiguous interpretations, while we do not strive to avoid them, but on the contrary, actively use such ambiguity in social conversation and in indirect speech. For example, when one person at the table asks another, “Can you serve salt?”he, as expected, gets the salt, and not the answer at all, to the question posed. Such questions and phrases are "ineffective, cause frequent misunderstandings and seem inappropriate," but they are used everywhere ^[9]. N. Chomsky noted in this regard that: "Language design as such turns out to be dysfunctional in many ways." In his opinion, the language is designed as a system that is beautiful, but, in general, not so usable. The language is not utilitarian, but rather created for beauty, although it has functions that allow it to be fully used for everyday purposes of our lives. N. Chomsky thus argues that the language system is elegant, but poorly designed, while biological systems are not designed that way at all. They are largely redundant for reasons that have a plausible functional explanation. The question of why language should differ so much from other biological systems is a scientific problem, and in some ways even a mystery ^[12].

Today, a large number of different theoretical concepts are presented in the scientific literature devoted to the problem of language evolution. However, in this article we plan to turn to the evolutionary approach actively used abroad in the study of this issue. It is well known that in order for any new biological traits to arise and consolidate in evolution, they must give a selective advantage, even if it is small and inconsistent, and such advantages are usually associated with nutrition, protection, reproduction or a combination of them. In the paradigm of evolutionary biology, there is no doubt that selection is the only way to explain the origin of language and other unique abilities peculiar to our species ^{[13; 14; 15]}. In this regard, one of the most promising evolutionary concepts for the development of human speech skills is Jeffrey Miller's theoretical model, which assumes the evolution of a courtship culture, where culture can be considered as a stage on which the development of verbal skill, creativity, humor and speech took place ^[3]. It is worth noting that the influence of courtship culture on the evolution of speech remains an insufficiently covered topic in the Russian scientific literature, while there are practically no empirical works exploring this topic in Russian.

The key place in Jeffrey Miller's model is occupied by the issues of the influence of sexual selection on speech. Sexual selection, as you know, is a very special evolutionary process, and the qualities that it forms also have special properties. In his book The Seducing Mind, Jeffrey Miller ^[3] points out that an important distinguishing feature of the forces of sexual selection is the fact that special qualities attractive to the opposite sex are usually well developed in mature individuals, but not in young ones.  And as a rule, male representatives demonstrate them brighter and (or) louder. These devices can be quite pretentious and "expensive": everyone knows the classic example of the result of the forces of sexual selection — a peacock's tail is a beautiful, but hardly conducive to invisibility, speed and maneuverability of its owner. Such features, which are not always utilitarian, but supported by sexual selection, following the principles of Fischer amplification, become very attractive to individuals of the opposite sex ^[16]. As a rule, these signs of attractiveness indicate good genes of their owner, because it is unlikely that their burden will be overcome by an individual who is sickly, exhausted, injured or burdened with harmful mutations. In addition, sexual selection makes some elements of mating behavior so complex and expensive that not too "high-quality" individuals cannot even think about them. The severity of attractive traits varies greatly among different individuals, while during courtship all possible markers of individual differences in health, intelligence, language abilities, and even in moral qualities, and therefore in fitness, play the most important role ^{[3; 17]}. Thus, Miller comes to the conclusion: all the brightest possibilities of the human mind — the ability to master language, practice art, build a worldview, develop a sense of humor and creative intelligence — are quite suitable for describing the products of evolution that arose under the influence of the forces of sexual selection.

The data on the history of the human life cycle also correspond to the key concepts of the theory of sexual selection. And although the basic structure and functions of language are laid down in childhood, mastering language as a social tool — a fluent and flexible means of oral communication, a tool for influencing and manipulating the opinions of others, as well as a performative means of communication — does not approach its advanced level of proficiency until adolescence and adolescence. It is at this stage of development that the means of performative speech can provide an advantage in the competitive struggle for sexual partners and become an active tool for increasing one's own attractiveness and one's own status. It is assumed that the evolutionary force of selection, the pressure of which reaches its peak precisely in adolescence, apparently consolidated such complex speech behavior. According to the assumption of researchers of the peculiarities of the human life cycle, it is quite possible that in our evolutionary past individuals with longer intervals between infancy and puberty and greater speech progress in the intermediate stages of adulthood reached a higher level of speech and verbal behavior and, consequently, became more competitive in social interactions ^[18].

The issues of the manifestation of speech functions in late adolescence and adulthood are studied in detail in the 2006 work of John Locke and Barry Bogin "Language and life history: a new look at the development and evolution of human language" ^[19]. The authors note that it is in adolescence that the linguistic diversity of speech begins to flourish, a rapid growth of vocabulary is observed, more subtle grammatical constructions appear, idiomatic expressions, slang phrases and words enter speech ^[20]. Another important area of adolescent speech development is associated with an increase in its speed, speech becomes fluent.  At this age, there is a significant improvement in the functions of the respiratory system, which can affect some aspects of speech and voice ^{[21; 22]}. For the first time, social conversation appears in communication — mainly relational use of speech, in which the topic of communication is other people ^[22]. This predisposition to discuss other people (gossip) is steadily increasing in adolescence, especially in girls ^[23], whereas the tendency to tease peers is more obvious in boys.  Some functions of speech that go beyond the semantic and pragmatic side of it, which are traditionally associated with the transmission of information, are also revealed: usually these new, pragmatic elements include jokes, flattery, deception, skillful negotiation, persuasion and sarcasm ^{[24; 25]}. These skills, as a rule, are ignored by teachers and linguists, who attach more importance to grammar and logic of presentation of thought ^[26]. However, it is precisely these linguistic innovations that contribute to the achievement of two important goals facing young people: improving personal status and success in relationships with the opposite sex. At the same time, the emphasis on the use of a variety of speech turns becomes particularly important quite late, since the skill of mastering such means of expressive speech as idioms, metaphors, speech sarcasm and rhyme approaches an advanced state only during late adolescence and adolescence.

Teenagers are not just learning additional features of their native language — they are actively practicing new rules for its use.  It is at this age that adolescents modify the material studied at earlier stages, thereby changing their native language in some of its aspects ^[27]. P. Eckert concluded that the relatively high degree of phonological innovations in the adolescent age group indicates that it is the peculiar subculture of adolescents that is the soil on which they are fixed important phonological and stylistic changes in speech ^[28]. At the phonological level of the language, changes often associated with an increase in the complexity of articulation serve the purpose of identifying members of youth social groups ^[29]. At the same time, it is noted that such non-standard forms of pronunciation occur mainly in young people, and not in girls.

It is also known that children and adolescents who change their language environment perfectly assimilate dialects and phonetic markers typical of their new peer group ^{[30; 31;32; 33]}. While the first learned native language, used exclusively in the family, suffers from incomplete assimilation in immigrant families (English incomplete acquisition ^[34]) and becomes de facto only a second language ^[35]. These data are somewhat inconsistent with the assumptions about the leading force of kin selection and kin communication in glotogenesis ^[36], but they also emphasize the paramount importance of the reproductive period in the speech self-identification and self-expression of an individual ^[3].

The most pronounced effect of the forces of sexual selection begins to manifest itself during flirtation, while verbal signs of attention play a huge role in attracting a partner. And although the verbal manifestations of sexual flirtation during courtship include only a small percentage of the individual's linguistic capabilities, it is this small proportion of speech activity that gives the strongest evolutionary effect.  After all, during acquaintance and the exchange of first phrases, the most important decisions affecting reproductive behavior are made: the interlocutor is approved or rejected as a possible sexual partner, including on the basis of what he (or she) says ^[3]. Analyzing the process of language evolution, it was this initial period of communication between young people that William Deacon singled out separately ^[37]. In his view, the reproductive dilemma facing our ancestors required people to create symbolic communication systems and further exchange them; transfer abstract concepts, symbols, a kind of "social arrangements" (for example, promises or obligations to someone).  In fact, the first signs and symbols were something like marriage contracts, evidence of the fact of long-term monogamy between a specific man and a woman. They had to be recorded, approved and implemented by both these individuals and the group as a whole. Thus, William Deacon's reasoning, including logically, converge in understanding the evolution of language, as well as the means of seduction, which Miller talks about: that is, a tool that allows you to symbolically and colorfully describe your future obligations, and thus able to produce the desired effect on an individual of the opposite sex and his (her) environment.

Indeed, in a broad sense, everything we say in public has a tremendous impact on our social status and personal attractiveness in the eyes of potential partners and society.  Thus, speech can also play a significant role in intra-gender competition, since the oratorical qualities of rivals are subject to strict evaluation by listeners. In this regard, traditional and non-written societies may be of particular interest for the study of the evolution of speech, since such societies seem to be more consistent with societies of the distant past, in which our evolution took place ^[38]. An appeal to ethnographic data can give us a clearer idea of the initial adaptive meaning of human speech and verbal behavior.  Modern researchers of the evolution of speech are lucky that it was non-written societies that were a popular research target for anthropologists of the past. The analysis of the ethnographic material shows that literally everywhere in traditional societies, anthropologists noted the belief in the "magical" power of the word ^[39].  At the same time, in the studied and described societies, the true power of the word was most often available to those members of the group who could use an exceptionally wide range of words and phrases "decorated" with intersperses of peculiar expressions and phrases that were not included in the more limited lexicon of listeners ^{[40; 41; 42]}. The content of such speech included archaic or esoteric language metaphors, metonymic phrases, riddles and special prosodic elements, as well as sonorous phrases ^{[43; 44; 45]}. These features of the speech of group leaders have been noted by ethnographers in Melanesia, Amazonia, Africa and North America.

In many non-written societies, speech, status and power are closely linked.  Thus, among the Maori, "oratory is the main condition for participating in the struggle for power" ^{[46, p. 50]}; in central Peru, the Amuesha people describe a real leader as a person who wields power through his words ^[47], Ethiopia, where among the Mursi "the most frequently mentioned attribute of an influential person is his ability to perform well in public" ^{[48, p. 176]}, Central Brazil, where "performing in a square is described as a "politically important act" ^{[49, p. 185]}, in the Northern Transvaal, among the Venda people, the greatest honor is given to those who can manipulate in words and sentences; in the Trobriand Islands, tribal leaders, or "big men", were also called "rhetorical goons" ^[50], in South Africa, the Tshidi people consider oratory to be an important component of political success and a means by which politicians demonstrate their acumen ^[51], in South Africa America believed that public speaking was more than a privilege, it was the duty of a leader. It is on him that the burden of owning words falls. ^[52].

It is also interesting that many speakers in traditional societies are men. For example: among the Limba people in Sierra Leone, the ability to speak well is a specifically masculine quality ^[53]. In the Ethiopian village studied by Turton ^[48], it was the prerogative of adult men to speak. Speakers in South Bali, according to M. Hobart (1975), were, as a rule, adult men between the ages of thirty and sixty, enjoying a reputation for their knowledge of the law and oratorical persuasiveness ^[54].

Male speakers usually have their own audience, and the result of a verbal victory or defeat can affect their statuses ^[55]. This audience includes both women and men. Ruth Finnegan ^[53] wrote that among the Limbo people, in a situation where a man speaks, a woman is expected to listen carefully, express her respect and appreciation.

Research on the relationship between speech and gender features has a long and difficult history. And, although gender differences in speech are most often associated with culture ^[24], there are a number of speech features characteristic of each gender that manifest themselves equally in different cultures.  First of all, psychologists note the widespread craving of young men for verbal duels, which is certainly related to physiology. And in this sense, the association of testosterone with physical aggression is most obvious in men ^{[56; 57]}. It is assumed that for young men who have high testosterone levels due to their young age, the use of verbal sparring, threats and sarcasm instead of direct physical clashes threatening to cause significant harm can be a very successful adaptive solution ^{[58; 59]}.  This hypothesis is also consistent with the fact that verbal duelists "lose their face" in the eyes of others, and the competition always stops if the participant begins to "get really angry and turns to fists" ^[60].End of the form

However, when teenage girls are aggressively opposed to each other, they more often use gossip, through which they often want to gain the support of their peers, at the same time gossip allows girls to harm the reputation of their rivals. It is worth noting that girls are significantly superior to boys in this "skill". Similar to the participation of men in public speaking, these differences in speech behavior between the sexes manifest themselves in late adolescence, cover a number of different cultures and persist into adulthood ^{[61; 62; 63]}. As an example, we can cite the ethnographic notes of Harry Gossen ^{[64; 65]}, who found that among the Chamula people in Mexico, the ability to conduct a good verbal duel is one of the earliest signs of a man's social maturity, intelligence and linguistic skill. Our ethnographers of the IXX century also noted these sex differences. So in Belarusian villages, "in the society of women, women amuse themselves with songs, riddles, and stories when men are testing physical strength, selfish games only in groups of men." ^[66].

But what is most significant for our article is the fact that the gender differences universally observed by ethnographers reveal a dissociation between language and performative speech.  And although, approaching maturity, men and women have approximately the same knowledge about the structure and linguistic and grammatical content of their native language, they obviously use this knowledge in different ways.  It is assumed that performances and performative speech play a certain role in the formation of youth. The desire of young men to actively attract attention to their person, apparently, indicates a whole set of newly acquired masculine qualities. After all, there is a reliable direct relationship between the propensity for public speaking and the level of testosterone in the blood.  Testosterone, for example, correlates with the boldness with which people enter a room, as well as with a predisposition to work in public, for example on a theater stage or in a courtroom. It is quite possible that this hormone may contribute to the choice of such a profession.  So, in some studies, actors actually had a fairly high level of testosterone ^[67], and lawyers had 30% higher levels of this hormone than the average in the population ^{[68; 69]}.

It is characteristic that men with a low, deep voice tone have a relatively higher testosterone content, and listeners usually consider them more dominant and attractive ^{[70; 71]}. A number of experimental studies have shown that women prefer low male voices, especially when they perceive them in conditions of flirtation and close communication ^{[72; 73]}. At the same time, the preference for a partner with a deeper and lower voice timbre increases during periods in which women are in the peak phases of the ovulatory cycle, when estrogen levels are highest ^{[74; 75; 76]}. Experimental work has shown that, as expected, a lower voice timbre is significantly associated with reproductive success in men ^{[77; 78; 79; 80]}. It was also reported that the ratings of the voice attractiveness of the opposite sex predicted the age of sexual initiation and the number of sexual partners fairly accurately ^{[81; 82]}. The authors of the 2021 study conclude that voice could be an important parameter of partner choice in human evolution ^[72], which is consistent with previous work ^[83].

Another important parameter proving the importance of performative speech for representatives of the stronger sex was the work evaluating the lexical component of the speech of the subjects. So, Bradley Franks and Kate Rigby showed that it was men who, as a rule, were more creative in choosing phrases in their oral speech when they were tested by an attractive young woman or when testing took place in a competitive environment with other men ^[84]. It was also found that young people used more rarely encountered words in a test simulating a date with a younger woman than with a more mature woman ^{[85; 86]}. In another experiment, the female subjects preferred a partner with an attractive manner of communication, both in the context of short-term and long-term relationships. They made their choice based on an analysis of the lexical diversity, grammatical complexity and fluency of the intended partner's speech ^{[87; 88]}.

A curious phenomenon of the action of the forces of sexual selection was revealed by an international team of researchers ^[89], who showed a clear preference for a partner with a sense of humor. As you know, humor requires creativity and intelligence — that is, the same abilities that are necessary to create works of art, music or literature ^[90]. It has been shown that although both women and men prefer a partner with a sense of humor, women prefer partners with an active sense of humor, whereas men seem to prefer partners who are receptive to their humor ^[89]. Indeed, it has been confirmed that speech full of humor and jokes is associated with the speaker's intelligence, and it is these qualities of speech that quite accurately predict reproductive success in men ^[91].

Studies examining associations of musical abilities and attractiveness are also promising, given the fact that both language skills and musical abilities are closely intertwined with a whole complex of human neurocognitive systems ^[92]. In this regard, Vanessa Slaming and John Mining ^[93] suggested that high prenatal exposure to androgens, as evidenced by In their opinion, the low finger index (a lower value of the ratio of the length of the second and fourth fingers 2D:4D), which is a fairly well-studied marker of psychological and physical masculinization, also directly correlates with individual musical abilities. And these abilities, in turn, can serve as markers of high fitness (that is, the quality of a partner) when evaluated by women. It is interesting to note in this regard that a number of studies have shown that women during ovulation really tend to choose performers of complex musical compositions ^[94]. Thus, the authors of the study suggest that in the past, musical abilities, along with developed verbal skills and humor, could have been actively supported by sexual selection ^[93].

The richness and beauty of speech are also directly related to the speaker's social class ^[95]. In the work of Hart and Risley, which was sensational at that time ^[96], the number of words that children heard at home was calculated, which was recorded by recording and transcribing weekly conversations in the homes of the children being tested. The results were disappointing: children from disadvantaged families heard an average of about 616 words per hour, a child from the working class 1,251 words per hour, while children from specialist families heard about 2,153 words per hour. Thus, in one year, extrapolating the collected data, one would expect 11 million words addressed to children in professional families, 6 million words addressed to working-class children and only 3 million words addressed to children from families living on benefits. But in addition to the quantitative differences in the language environment surrounding us from early childhood, numerous qualitative differences have also been found that affect the child's speech and its future characteristics. These qualitative differences in the language environment are associated with many aspects of the language surrounding the child — its phonology, vocabulary, syntax, semantics and pragmatics of language, richness of vocabulary, average length of utterances, frequency of repetition, prosody, stimulation of joint communication, semantic randomness, decontextualized use of language such as narratives, and many others. Most of the identified characteristics stimulating the child's speech are interrelated, but most importantly, they all directly correlate with the socio-economic status of the family, which is usually correlated with parental education. At the same time, indicators of the specific features of the language environment closest to the child significantly affect the child's future language abilities. And longitudinal studies using daily recordings of spoken home speech have confirmed that the language array that children hear at the age of 16 or 18 months predicts vocabulary growth and language acquisition rate quite accurately at an older age ^{[97; 98; 99]}.

In adolescence, however, practical exercises in rhetoric are required to master oratory ^[100]. For example, classes are important for students, "including trainings on speech techniques, various communicative and speech trainings (for the development of spontaneous speech, modeling and acting out various communication situations, etc.), rhetorical games ... self-presentations, solemn (entertaining), informative, persuasive speeches and their further analysis; as well as the analysis of oratorical speeches in movies and TV programs" ^[101]. In this sense, maintaining speech skills at a high level implies not only a rich language environment from early childhood, but also the availability of sufficient time after reaching adulthood, which can be devoted to learning, writing, as well as communication, small talk, and all this can also serve as an indirect sign of belonging to a certain social circle, at least having enough time, free from the search for what is called daily bread.

In addition to richness, beauty and lexical complexity, individual speech contains many other verbal signals, including those determined by evaluating pronunciation features and through other phonological markers present in it. For example, a recent English study showed that men who pronounced certain phonemes more clearly were rated by women as more attractive for long-term relationships, while other men perceived the owner of such a well-articulated speech as more statuesque.  According to the authors of the study, the results obtained indicate that aspects of pronunciation that affect the perception of prestige and long-term attractiveness of a partner may indicate a high socio-economic status of their owner, probably due to the crystallization of certain articulation patterns during a critical period of linguistic development ^[102]. A study by Chinese colleagues showed a connection between two stylistic linguistic features of the capital's Mandarin Chinese language. Mandarin Chinese). In a 2005 paper, the speech of managers of foreign financial companies was compared with the speech of managers of state-owned companies. Managers in the foreign financial sector represent the emerging yuppie culture and, as highly paid employees by global standards, represent the vanguard of ongoing social change in China. According to the author, employees of such international companies stand out for their cosmopolitan views, which is characterized, among other things, by a style of speech that sharply contrasts with the speech of managers of more traditional state-owned enterprises. Thus, the author of the study showed a significant difference in the use of language in the studied two social strata in Beijing ^[103].

In conclusion, I would like to emphasize once again that sexual selection is a powerful evolutionary mechanism capable of forming certain characteristics that may be both useful and not very important for the survival of an individual. At the same time, the most significant fact for the directed evolution of sexual preferences is that a trait attractive to the opposite sex should not be too cheap for its bearer, because in this case it can be easily "forged" ^[104]. And potential deceivers who dismantle an attractive but "cheap" feature may in fact be deprived of the accompanying qualities of fitness. As a result, an important biological mechanism of selectivity loses all its meaning, because when choosing a partner, it becomes impossible to focus on the presence of such an unreliable trait. However, if the trait is really burdensome, a "weak" individual will not be able to simulate it ^[104]. And, returning to the definition of sexual selection that we gave at the beginning of our theoretical review, we can assume that some elements of public speaking are indeed complex and "expensive", so that socially unsuccessful individuals cannot even think about them ^[3]. We believe that certain linguistic markers of high social status may well be picked up and enhanced by sexual selection. Thus, eloquence, the timbre of the voice, the manner of conducting a conversation can serve not only as an indicator of creativity and ingenuity of the speaker, markers of masculinity and fitness, but also important signs indicating belonging to a certain social environment, social class.