Denmark

Social primates exhibit a vast behavioural and cultural repertoire. Understanding the ontogeny of sociability in primates can bring important findings in comparative studies between human and non-human cultures. In this context, our objective was to analyse the development of the social personality of 12 wild capuchin monkeys (Sapajus libidinosus) and test if sex and monkey identity affected the social personality. We used videos recorded in the wild during the first 3 years of life of 6 males and 6 females and analysed the rate of emission of affiliative social behaviours, such as grooming, lipsmacking and others. We used GLMMs and tested the repeatability of behaviours for statistical analysis. The results showed low repeatability for monkey identity and sex as random effects The population exhibited high values of inter and intraindividual variance in the emission of behaviours, especially during the first year and a half of life, that is the infancy of S. libidinosus. The repeatability values stabilised in the juvenile period, but remained low. Our results show that social personality is not yet established in the first three years of life for these primates. Longitudinal studies following the individuals until adulthood are necessary to understand if and when personality is consolidated in capuchin monkeys.

Cultural Evolution Society 2022

The development of social personality in a wild neotropical primate

social bahaviour

animal personality

animal behavioural ecology

### 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 
<br><br>

Please click on the button bellow if you want to watch the videos

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.

poster

Introduction: The observation that child-directed speech (CDS) benefits language learning has been taken to suggest that this register is part of natural pedagogy – a suite of evolved pro-social communicative behaviours that use ostension to teach culturally relevant knowledge. While prosodic features of CDS appear universal, phonetic, morphosyntactic and lexical features tend to vary cross-linguistically. I argue that (a) this variation in CDS reflects different solutions to trade-offs between affective bonding and teaching, based on specific linguistic affordances and cultural constraints, and that (b) the way didactic features are incorporated into CDS is itself acquired and transmitted. <br>Evidence: Preliminary evidence comes from (a) comparisons of acted vs spontaneous CDS, where positive affect expression can render the latter suboptimal for language learning, (b) CDS of proficient L2-speakers which lacks some features of native CDS and (c) iterated language learning experiments in which learners who subsequently teach change transmission. Further evidence should come from tracing changes in teaching efficiency during cultural transmission under social vs asocial learning conditions. <br>Discussion: CDS may be a special case of conventionalisation of didactic features which can themselves be learned thereby reducing the individual cost of prosocial behaviours like teaching.

Learning to Transmit: The Acquired Nature of Child-Directed Speech

 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

 This presentation examines the transplant of the legal doctrine of assignment of contract in the Japanese legal system as a case of cultural evolution. Its main objective is to examine how the existing legal literature on legal transplants can be re-evaluated in the theoretical framework of cultural evolution. This presentation will be mainly based on qualitative analysis of legal and doctrinal sources of the legal systems involved, and on a general review of the comparative legal scholarship on legal transplants and legal evolution. This presentation rejects an essentialist vision of legal culture, according to which legal evolution occurs only in stages and legal transplants can happen only between legal cultures which share a common tradition. Instead, this presentation shows that legal transplants are possible despite hurdles such as differences in language, culture and geography. It also reveals that legal transplants involving highly technical legal doctrines without political coloration, such as the doctrine of assignment of contract, can occur without any decisive relationship to legal culture. Based on these findings, this presentation strongly suggests that legal transplants should be studied as typical cases of cultural evolution.

Legal Transplants as Cultural Evolution: The Doctrine of Assignment of Contract in Italy and Japan

 Conflict is a persistent feature of primate societies. Although sociability has valuable benefits, such as protection against predators or access to resources, maintaining peaceful relationships with other group members can be costly for individuals. Conflict episodes within a social group promote physical contact and changes in social dynamics. All social animals engage in episodes of conflict and aggression for dominance, control of resources, food, sexual partners, or territories. To restore social balance, primates display appeasement gestures that may repair relationships after fights. One way to restore harmony after is through sexual behavior. Non-conceptive sexual behaviors have been described in most primate species. These are explained by its communicative or sociosexual functions, which include tension regulation, dominance signaling, ties strengthening, and reconciliation among others. In this study, we systematically reviewed literature on primate conflict and resolution to determine how frequently sexual behavior has appeasing function. Results showed that closely related species like bonobos (Pan paniscus) and chimpanzees (P. troglodytes) routinely use sexual behavior for conflict resolution. However, it is still necessary to investigate reconciliatory sexual behavior in other primate species.

Make love, not war: Conflict and sexual reconciliation in primates

 Irons (2001) and Sosis (2003) proposed that some actions are “hard” or “costly” to fake signals of altruism. If it is harder for non-altruists to perform an action than for altruists, associating with other signalers can solve cooperation dilemmas. This invites intuitive reference to costly signaling theory from animal behavior, but this theory describes signals of quality, not intent. Further, costly and hard are open to interpretation. It may take extra effort to perform the signal dishonestly. Deception may be unlikely to be innovated. Socially learning of deception may be inhibited as deceivers present as honest. Signal receivers may invest in false-signal detection. These all present distinct dynamics. Multiple interpretations of the verbal model of costly/hard to fake signals are mathematically formalized and implemented in social learning models. Analytic solutions for evolutionary equilibrium are derived for each. Under a range of conditions for some but not all interpretations, such signals and altruism spread through a population. Where deception entails some cost or is less likely to be learned hard to fake-signals can lead to group success through altruistic cooperation. A particularly interesting case is where deceptive parasitic free-riders paradoxically benefit the group by amplifying recruitment via effective false advertising: “Useful Liars”.

Credibility and Deception: modeling deceptive signals of intention to cooperate

 I study the impact of exposure to large adverse shocks on people's normative beliefs. Combining data on the occurrences of conflicts, epidemics, and other natural disasters with large-scale survey data covering hundreds of normative beliefs, I make four findings. First, individuals surveyed in the weeks after a shock hits in their vicinity shift their normative beliefs closer to the local modal beliefs, place more importance on norm adherence, and exhibit a greater willingness to sanction norm deviations. Second, the effect is found for normative beliefs across many domains, pointing to a psychological mechanism rather than a strategic response to shocks. Third, shocks can lead to belief polarization if the local modal beliefs differ across groups before a shock hits. Fourth, examining within-country variation in shocks experienced during early lifetime across cohorts, I find that the effect persists.

Aftershocks: How Wars, Epidemics, and Other Natural Disasters Tighten Social Norms

Religious sermons reinforce and transform the ideas and values of local communities. Prior work indicates sermons serve important functions for individuals and groups, but many key questions could not be addressed due to limited corpus size. The present research uses natural language processing on a corpus of 50,000 geo-tagged sermons from five Christian denominations delivered between 2019-2020 in the United States. We aim to understand how sermon content is associated with—and affected by—socio-ecological context. This requires two main analyses. First, accounting for spatial autocorrelation, we correlate sermon content with state-level variables, including tightness, political orientation, and prevalence of natural disasters. Second, we use event-based analyses to examine how local sermon content is influenced by natural and man-made disasters. Preliminary analyses indicate our analyses are feasible: Sermons are distributed sufficiently across states, and we have quantified the prevalence of psychologically relevant topics in each sermon. We await the results of our main analyses. It is now easy to utilize rich data sources, like transcripts, that directly capture phenomena of interest. Religious sermons are an untapped data source for scholars to examine how religious institutions transmit culture and interact with the socio-ecological environment.

How religious sermon content is associated with—and affected by—socio-ecological context: Analyzing 50,000 American sermon transcripts from 2019-2020

Introduction: Music and language are both found in all societies. But did humans evolve to make music, or is our musicality a byproduct of language evolution? Surprisingly, there remains little data on which aspects of music and language are shared or distinct across cultures, due to the limitations of automated acoustic analysis and the lack of cross-cultural datasets with human annotations. Approach: We combined objective acoustic analysis with subjective speaker annotations to compare recordings of singing, lyrics recitation, spoken description of the song, and the instrumental version across diverse languages. Findings: Pilot analyses of recordings in five languages (Japanese, English, Yoruba, Farsi, and Marathi) suggest that tempo is the feature that most strongly differentiates speech and song (song is slower), while melodic interval is most similar (both speech and song are characterized by small intervals <700 cents). Discussion: We will use a Registered Report framework to rigorously test candidate features on a sample of over 50 languages, revealing cross-culturally shared and distinct features of speech and song, and shedding light on the evolution of language and music.

Similarities and differences in a cross-linguistic sample of song and speech recordings

People are generally biased toward hearing and producing rhythms composed of simple integer ratios. However, the preference for specific rhythm structure is also significantly modulated by experience and differs across cultures (Jacoby and McDermott 2017). The role played by distinct musical experiences in developing the specific rhythmical categories remains unclear.
To address this issue we conducted a study on haptic rhythm reproduction on congenitally deaf people, that is, a population which has never have been exposed to auditory music. 20 congenitally deaf subjects (aged 18-40) participated in an experiment based on a haptic version of the iterating learning rhythm procedure(Jacoby and McDermott 2017) The rhythmical sequences were presented on the participants’ torso using a haptic strap, and subjects were asked to reproduce rhythmical sequences by tapping synchronously along with the stimuli. Each participant’s reproduction of a rhythm provided the seed for the next rhythm iteration, so that perceptual priors could be estimated.
Surprisingly, we found that the deaf individuals have rhythmic categories that are similar to those revealed in previous studies on auditory rhythm in the general population. Like hearing populations, deaf subjects exhibit a tendency toward integer ratio rhythms. Comparing to hearing US subjects, they also tended to have significantly more of the simple categories (such as 1:1:1 ratio), and significantly less complex rhythms categories (i.e.1:2:3 ratio).
Our results show that perceptual priors for specific rhythms can be developed independently of auditory and musical exposure.

Rhythm categories without auditory experience? Perceptual priors reveal by haptic rhythm reproduction in the congenitally deaf subjects.

Previous research suggested changes in anxiety and mood connected with fluctuations of progesterone during menstrual cycle. These fluctuations could in turn lead to behavioral patterns connected to heightened states of anxiety. For example, in humans and non-human animals, ritualized behavior has been linked to states of intense stress and anxiety in a range of studies. In a pre-registered (osf.io/fq7sm) longitudinal study (36 days), free-cycling female participants regularly marked their day of the cycle, symptoms connected with the menstrual cycle, levels of anxiety, and activities they performed. These activities were evaluated by independent coders on the characteristics of ritualized behavior. The main prediction of the study were that psychological changes, specifically heightened anxiety, and perceived stress during the luteal phase, would lead to both an increase in the types of ritualized behaviors and higher intensity of those behaviors. We have not observed any differences in anxiety or stress between luteal and follicular phases, but higher anxiety (independent from phase) was positively correlated with more ritualized behaviors.

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Learning to Transmit: The Acquired Nature of Child-Directed Speech

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