Denmark

 Humans are unique in their sophisticated culture and diverse societal structures, their complex languages, and their extensive use of tools. According to the human self-domestication hypothesis, this unique set of traits may be the result of an evolutionary process of self-induced domestication, in which humans have evolved to be less aggressive and more cooperative. Notably, the only other species that has been argued to be self-domesticated besides humans so far is bonobos, resulting in a narrow scope for investigating this theory beyond the primate family. Here, we propose a new animal model for studying self-domestication: the elephant. First, we support our hypothesis with an extensive cross-species comparison which suggests that elephants indeed exhibit many of the features associated with self-domestication (e.g., reduced aggression, increased prosocial behavior, extended juvenile period, increased play behavior, socially regulated cortisol levels and complex vocal behavior). Next, we present novel genetic evidence to reinforce our proposal, showing that genes positively selected in elephants are enriched in pathways associated with domestication traits and include several candidate genes previously associated with domestication. Together, our findings underpin the idea that elephants, like humans and bonobos, may have been self-domesticated.

Cultural Evolution Society 2022

Self-domestication in non-human species: elephants as a case study

### Welcome to the fourth Cultural Evolution Society Conference, CES2022! 

As last year, Underline will support the online component of the conference. The ongoing COVID-19 pandemic is causing a great deal of uncertainty for all of us. Therefore, we seek to offer a hybrid format that will hopefully allow some folks to travel to Aarhus, others to meet up locally or regionally in CES hub-lets, and other yet to participate online. The field of cultural evolution is growing in size and scope; its theories, methods and applications - both academic and applied - are getting ever more robust. Do join us in what promises to be an exciting exchange of ideas and a celebration of our field.

##### ***For SoMe interaction and live tweeting please tag @CulturalEvolSoc and use #CESconf2022***


#### The CES 2022 local organising committee
* Luseadra Joy McKerracher
* Jesper Sørensen 
* Niels Nørkjær Johannsen 
* Benjamin Grant Purzycki 
* Mette Løvschal 
* Felix Riede
* Iza Romanowska 
* Karsten Olsen

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The field of cultural evolution is growing in size and scope; its theories, methods and applications - both academic and applied - are getting ever more robust. Do join us in what promises to be an exciting exchange of ideas and a celebration of our field.

technical paper

 Humans evolved cultural cognition that allows for the fastest and highest fidelity social learning in the animal world. Our derived cultural cognition enhances cooperative-communication, develops early in infancy and is not shared with other great ape species. I will present evidence that domestic dogs (Canis familiaris) possess cognition that allows for similar forms of cooperative-communication as seen in human infants. I will make the case (relying on comparisons between dogs, wolves and foxes) that these human-like abilities evolved in dogs convergently as a result of self-domestication. The unusual skills dogs demonstrate for working and communicating with humans are by-products of selection for friendliness toward humans that altered their cognitive development. I will also argue that dogs provide a model for how human cultural cognition evolved through a similar process of self-domestication.

Dogs and humans evolved cooperative-communication through self-domestication

**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

Our theme of this session is to build a bridge between two continents – Continent “E” of
Evolutionary scientists, Continent “L” of Legal scholars. Building this bridge offers a new
horizon. These two Continents meet today. We follow up a dialogue between Gintis, H. on
“E” and Jones, O.D. on “L” (2007, in Behav. &amp; Brain Sci.) as a good precedence.
The Continent “E” is populated with Big Names, who had cautiously avoided the term “law”
but practically dealt with evolution of law. They include theoretical model research by
Axelrod &amp; Hamilton (1981), Boyd (et al 2003), Bowles &amp; Gintis (2004; 2011), Sigmund (et al
2005), and empirical studies by Rand (et al 2011), Jordan (et al 2016), followed by
behavioral scientists Suchak &amp; deWaal (2016) who evidenced third-party punishment for
social norm enforcement among non-human primates (but modestly did not refer to “law”).
The other Continent “L” has also shown interest in Continent “E”. The Society for
Evolutionary Analysis in Law (SEAL, established by Jones, O.D.) also targets at “evolution
of law” per se. A SEAL member and laureate of Nobel Prize for Economics, Ostrom, E.
evidenced her keen interest in law’s evolution (1990, 1994). A German sociology giant
Luhmann was an early advocate of cultural evolution of law (1993; English 2004, OUP).
Building this bridge today is a big gain for science.

Introduction

**Author(s):** Kido, Y., Takezawa, M. People are willing to pursue virtues or social rules often incurring material costs. It has been argued that evolving such norm psychology was a crucial step on the path to large-scale human cooperation. Research on social norms has broadly identified two types of norms: injunctive and descriptive norms. It has been shown that if cooperative dilemmas were the only adaptive problem humans faced, the tendency to follow descriptive norms (i.e., conformity) would never evolve from scratch (Kido & Takezawa, 2021). However, conformity was selected for allowing us to develop adaptive behaviors over a wide range of domains. Thereby, it remains unclear how norm psychology and cooperation coevolve. In the present study, we explored the impact of exapted conformity by modeling the coevolution of cooperation and norm psychology. In our simulations, agents make a decision, maximizing a utility function that captures three motives: gaining material payoff, following injunctive and descriptive norms. Group and individual level selective pressures drive evolution of utility function. We show that evolved conformity could radically change what type of norm psychology is evolutionarily adaptive. Our findings suggest that injunctive norms encouraging only punishments will not be internalized under evolved conformity. Rather, humans tend to embody norms for cooperation per se and exhibit cooperation.

Coevolution of norm-psychology and cooperation under exapted conformity

**Author(s):** Nirjhor, M.S.A.; Nakamaru, M. Introduction: Division of labor is based on cooperation among players with various roles on various network structures. It is common in our society but rarely studied from the viewpoint of the evolution of cooperation. We focus on the effects of two possible sanction systems: the defector-sanction system and the 1st role-sanction system, on the evolution of cooperation in the linear division of labor arranged in a unidirectional linear chain. Method: By using the replicator equations of the asymmetric game, we analyze our model; there is a finite number of roles each of which is assigned to one group with cooperators and defectors. A cooperator in an upstream group produces or modifies a product, paying a cost of cooperation, and hands it to a player in a downstream group who obtains a benefit from the product. Costs and benefits are different among groups. If players in all roles cooperate, a final product can be completed. However, if a player in a group chooses defection, the division of labor stops, the final product cannot be completed, and all players in all roles suffer damage. Results & Conclusion: We find that not the benefit but the cost matters to the evolutionary dynamics. We also find that the probability of finding a defector and the initial demography of the groups determine which sanction system promotes cooperation.

Effects of sanction systems on the evolution of cooperation in the linear division of labor with finite roles

**Author(s):** Andrews, K; Fitzpatrick, S; Westra, E Social norms—rules governing which behaviors are deemed appropriate or inappropriate within a given community—are typically taken to be uniquely human. Recently, this position has been challenged (Andrews 2020; Danón 2019; Fitzpatrick 2020; Kappeler et al. 2019; von Rohr et al. 2011). The view that norms are human unique stems from commitments regarding the psychological capacities required for having them, and skepticism that animals possess these prerequisites (Birch 2020; Rakoczy and Schmidt 2019; Schlingoff and Moore 2017; Tomasello 2016). However, among norm cognition researchers there is little agreement about the cognitive architecture that underpins social norms in humans. This makes empirical study of animal social norms difficult at this stage. To make progress, we draw inspiration from the animal culture research program, and offer an an operationalized account of social norms. We propose examining normative regularities: a socially maintained pattern of behavioral conformity within a community (Westra and Andrews, in preparation). We suggest methods for studying social norms in wild and captive primate populations, and examine the implication of animal social norms for theories of cultural evolution.

Investigating social norms in nonhuman animals

Introduction: Inferences about others' minds seem necessary for successful human social life, but Opacity of Mind (OoM) norms against mentalizing in small, traditional communities challenge this notion. This research employs the concept of relational mobility – or the capacity to freely move among social groups – as an index of the socio-cultural adaptive pressure that might promote the evolution of mentalizing norms. Method: This research recruits Indigenous iTaukei Fijians with Opacity of Mind norms (n=90), New Zealanders with mind-centric norms (n=280), and Pacific people living in New Zealand (n=600) who live in a cultural middle-zone. I test whether preference for outcome focus (rather than a more mentalizing intent focus) can be explained by ToM measures or ecological factors like relational mobility with pre-existing mentalizing scales and vignettes assessing social judgments. Results: Results suggest OoM norms mitigate relational (im)mobility by shifting focus to external, observable behaviors, rather than focusing on intent which may be perceived as more hostile when relational mobility is low. Discussion: Cognitive capacities like mentalizing form the backbone of human social life. Core cognitive functions may be modulated to suit particular environmental constraints via inheritance pathways of norm psychology.

Do Opaque Minds Make Better Neighbors? Examining Relational Mobility as a Predictor of Outcome Focus Across Three Folk Theories of Mind

**Author(s):** Walldén, C; Gunst, A; Westerlund, M; Santtila, P; Antfolk, J. We tested the hypothesis that anti-immigration tendencies (e.g., discrimination and negative attitudes towards immigration) can partly be the result of intrasexual competition for mates, especially among heterosexual men. That is, the more an immigrant group is perceived as increasing intrasexual competition, the more anti-immigration tendencies will be displayed by natives. We predicted that native men would display more anti-immigration tendencies than women and that immigrant-specific variables (relationship status, ethnicity-specific prejudice concerning sexual behavior) would predict native men’s anti-immigration tendencies. We presented participants with online vignettes presenting a large group of immigrants of reproductive age and of the participant’s own gender entering into the participant’s home county. We manipulated the relationship status and ethnicity of the immigrant groups. After each vignette, participants reported their anti-immigration tendencies towards the described immigrant group. We also measured participants' self-reported mate access, mate value, and intrasexual competition. We recruited 485 Finnish adults between 25 and 44 years and used available data on their home county’s sex-ratio for their age group as a proxy measure for mate access. As expected, men displayed more anti-immigration tendencies than women and men reported more anti-immigration tendencies against immigrants from the Middle East compared to against immigrants from South-East Asia. Contrary to our hypothesis, intrasexual competition did not predict anti-immigration tendencies among men, but among women. We discuss these findings further.

Intrasexual Competition and Anti-Immigration Tendencies

**Author(s):** Schulze, J N; Denkinger, J; Oña, J; Poole, M M; Garland, E C Cultural transmission of behaviour is an important aspect of many animal communities ranging from humans to birds. Male humpback whales (Megaptera novaeangliae) sing a repetitive, stereotyped, socially learnt, and culturally transmitted song display that slowly evolves each year. Most males within a population sing the same, slow-evolving song type; but in the South Pacific, song ‘revolutions’ have led to rapid and complete replacement of one song type by another introduced from a neighbouring population. Songs spread eastwards, from eastern Australia to French Polynesia, but the easterly extent of this transmission was unknown. Here, we investigated whether song revolutions continue to spread from the central (French Polynesia) into the eastern (Ecuador) South Pacific region. Similarity analyses using three consecutive years of song data (2016-2018) revealed that song themes recorded in 2016-18 French Polynesian song matched song themes sung in 2018 Ecuadorian song, suggesting continued easterly transmission of song to Ecuador, and vocal connectivity across the entire South Pacific Ocean basin. This study demonstrates songs first identified in western populations can be transmitted across the entire South Pacific, supporting the potential for a circumpolar Southern Hemisphere cultural transmission of song and a vocal culture rivalled in its extent only by our own.

Humpback whale song revolutions continue to spread from the central into the eastern South Pacific

**Author(s):** Hersh, T; De Gregorio, C; Kwong, A; Whitehead, H; Gero, S; Rendell, L; Muldoon, M; Lewis, R; Soma, M; Anichini, M; de Reus, K; Berry, C; Ravignani, A Introduction: Small integer ratio (SIR) categorical rhythms—where intervals separating sounds are distributed around SIRs—dominate human music and some birdsong, and are thought to emerge from or foster cultural transmission of learned vocalizations. Other species with culturally transmitted, socially learned vocalizations should thus also have rhythm categories.
 Methods: We looked for categorical rhythms in sperm whale codas, Java sparrow songs, and harbour seal pup calls. All three species learn vocalizations, but only the first two show extensive evidence of culture. We calculated ratios of adjacent sound intervals and quantified whether there were significant distribution peaks at SIRs.
 Results: Sperm whale codas and Java sparrow songs exhibit SIR categorical rhythms. As in humans, exact ratio preferences vary by whale cultural group. In Java sparrows, sons mirror the rhythms of their social, but not genetic, father. Harbour seal pup calls show no evidence of categorical rhythms.
 Conclusions: These human/animal parallels emphasize that culture can drive rhythmic similarities in communication systems even when underlying sound production anatomies and acoustic environments differ.

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Self-domestication in non-human species: elephants as a case study

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Dogs and humans evolved cooperative-communication through self-domestication

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