Modern theories of human evolution foreshadowed by Darwin's Descent of Man

Modelling social norms: an integration of the norm-utility approach with beliefs dynamics

We review theoretical approaches for modelling the origin, persistence and change of social norms. The most comprehensive models describe the coevolution of behaviours, personal, descriptive and injunctive norms while considering influences of various authorities and accounting for cognitive processes and between-individual differences. Models show that social norms can improve individual and group well-being. Under some conditions though, deleterious norms can persist in the population through conformity, preference falsification and pluralistic ignorance. Polarization in behaviour and beliefs can be maintained, even when societal advantages of particular behaviours or belief systems over alternatives are clear. Attempts to change social norms can backfire through cognitive processes including cognitive dissonance and psychological reactance. Under some conditions social norms can change rapidly via tipping point dynamics. Norms can be highly susceptible to manipulation, and network structure influences their propagation. Future models should incorporate network structure more thoroughly, explicitly study online norms, consider cultural variations and be applied to real-world processes. This article is part of the theme issue 'Social norm change: drivers and consequences'.

Norm Dynamics: Interdisciplinary Perspectives on Social Norm Emergence, Persistence, and Change

Social norms are the glue that holds society together, yet our knowledge of them remains heavily intellectually siloed. This article provides an interdisciplinary review of the emerging field of norm dynamics by integrating research across the social sciences through a cultural-evolutionary lens. After reviewing key distinctions in theory and method, we discuss research on norm psychology-the neural and cognitive underpinnings of social norm learning and acquisition. We then overview how norms emerge and spread through intergenerational transmission, social networks, and group-level ecological and historical factors. Next, we discuss multilevel factors that lead norms to persist, change, or erode over time. We also consider cultural mismatches that can arise when a changing environment leads once-beneficial norms to become maladaptive. Finally, we discuss potential future research directions and the implications of norm dynamics for theory and policy.

The Anthropocene condition: evolving through social-ecological transformations

Anthropogenic planetary disruptions, from climate change to biodiversity loss, are unprecedented challenges for human societies. Some societies, social groups, cultural practices, technologies and institutions are already disintegrating or disappearing as a result. However, this coupling of socially produced environmental challenges with disruptive social changes-the Anthropocene condition-is not new. From food-producing hunter-gatherers, to farmers, to urban industrial food systems, the current planetary entanglement has its roots in millennia of evolving and accumulating sociocultural capabilities for shaping the cultured environments that our societies have always lived in (sociocultural niche construction). When these transformative capabilities to shape environments are coupled with sociocultural adaptations enabling societies to more effectively shape and live in transformed environments, the social-ecological scales and intensities of these transformations can accelerate through a positive feedback loop of 'runaway sociocultural niche construction'. Efforts to achieve a better future for both people and planet will depend on guiding this runaway evolutionary process towards better outcomes by redirecting Earth's most disruptive force of nature: the power of human aspirations. To guide this unprecedented planetary force, cultural narratives that appeal to human aspirations for a better future will be more effective than narratives of environmental crisis and overstepping natural boundaries. This article is part of the theme issue 'Evolution and sustainability: gathering the strands for an Anthropocene synthesis'.

Agentic processes in cultural evolution: relevance to Anthropocene sustainability

Humans have evolved culturally and perhaps genetically to be unsustainable. We exhibit a deep and consistent pattern of short-term resource exploitation behaviours and institutions. We distinguish agentic and naturally selective forces in cultural evolution. Agentic forces are quite important compared to the blind forces (random variation and natural selection) in cultural evolution and gene-culture coevolution. We need to use the agentic policy-making processes to evade the impact of blind natural selection. We argue that agentic forces became important during our Pleistocene history and into the Anthropocene present. Human creativity in the form of deliberate innovations and the deliberate selective diffusion of technical and social advances drove this process forward for a long time before planetary limits became a serious issue. We review models with multiple positive feedbacks that roughly fit this observed pattern. Policy changes in the case of large-scale existential threats like climate change are made by political and diplomatic agents grasping and moving levers of institutional power in order to avoid the operation of blind natural selection and agentic forces driven by narrow or short-term goals. This article is part of the theme issue 'Evolution and sustainability: gathering the strands for an Anthropocene synthesis'.

LRRC37B is a human modifier of voltage-gated sodium channels and axon excitability in cortical neurons

The enhanced cognitive abilities characterizing the human species result from specialized features of neurons and circuits. Here, we report that the hominid-specific gene LRRC37B encodes a receptor expressed in human cortical pyramidal neurons (CPNs) and selectively localized to the axon initial segment (AIS), the subcellular compartment triggering action potentials. Ectopic expression of LRRC37B in mouse CPNs in vivo leads to reduced intrinsic excitability, a distinctive feature of some classes of human CPNs. Molecularly, LRRC37B binds to the secreted ligand FGF13A and to the voltage-gated sodium channel (Nav) β-subunit SCN1B. LRRC37B concentrates inhibitory effects of FGF13A on Nav channel function, thereby reducing excitability, specifically at the AIS level. Electrophysiological recordings in adult human cortical slices reveal lower neuronal excitability in human CPNs expressing LRRC37B. LRRC37B thus acts as a species-specific modifier of human neuron excitability, linking human genome and cell evolution, with important implications for human brain function and diseases.

Comparative physiological anthropogeny: exploring molecular underpinnings of distinctly human phenotypes

Anthropogeny is a classic term encompassing transdisciplinary investigations of the origins of the human species. Comparative anthropogeny is a systematic comparison of humans and other living nonhuman hominids (so-called "great apes"), aiming to identify distinctly human features in health and disease, with the overall goal of explaining human origins. We begin with a historical perspective, briefly describing how the field progressed from the earliest evolutionary insights to the current emphasis on in-depth molecular and genomic investigations of "human-specific" biology and an increased appreciation for cultural impacts on human biology. While many such genetic differences between humans and other hominids have been revealed over the last two decades, this information remains insufficient to explain the most distinctive phenotypic traits distinguishing humans from other living hominids. Here we undertake a complementary approach of "comparative physiological anthropogeny," along the lines of the preclinical medical curriculum, i.e., beginning with anatomy and considering each physiological system and in each case considering genetic and molecular components that are relevant. What is ultimately needed is a systematic comparative approach at all levels from molecular to physiological to sociocultural, building networks of related information, drawing inferences, and generating testable hypotheses. The concluding section will touch on distinctive considerations in the study of human evolution, including the importance of gene-culture interactions.

Entropy and Cross-Level Orderliness in Light of the Interconnection between the Neural System and Consciousness

Despite recent advances, the origin and utility of consciousness remains under debate. Using an evolutionary perspective on the origin of consciousness, this review elaborates on the promising theoretical background suggested in the temporospatial theory of consciousness, which outlines world-brain alignment as a critical predisposition for controlling behavior and adaptation. Such a system can be evolutionarily effective only if it can provide instant cohesion between the subsystems, which is possible only if it performs an intrinsic activity modified in light of the incoming stimulation. One can assume that the world-brain interaction results in a particular interference pattern predetermined by connectome complexity. This is what organisms experience as their exclusive subjective state, allowing the anticipation of regularities in the environment. Thus, an anticipative system can emerge only in a regular environment, which guides natural selection by reinforcing corresponding reactions and decreasing the system entropy. Subsequent evolution requires complicated, layered structures and can be traced from simple organisms to human consciousness and society. This allows us to consider the mode of entropy as a subject of natural evolution rather than an individual entity.

Gradistics: An underappreciated dimension in evolutionary space

The growth of complexity is an unsolved and underappreciated problem. We consider possible causes of this growth, hypotheses testing, molecular mechanisms, complexity measures, cases of simplification, and significance for biomedicine. We focus on a general ability of regulation, which is based on the growing information storage and processing capacities, as the main proxy of complexity. Natural selection is indifferent to complexity. However, complexification can be inferred from the same first principle, on which natural selection is founded. Natural selection depends on potentially unlimited reproduction under limited environmental conditions. Because of the demographic pressure, the simple ecological niches become fulfilled and diversified (due to species splitting and divergence). Diversification increases complexity of biocenoses. After the filling and diversification of simple niches, the more complex niches can arise. This is the 'atomic orbitals' (AO) model. Complexity has many shortcomings but it has an advantage. This advantage is ability to regulatory adaptation, including behavioral, formed in the evolution by means of genetic adaptation. Regulatory adaptation is much faster than genetic one because it is based on the information previously accumulated via genetic adaptation and learning. Regulatory adaptation further increases complexity of biocenoses. This is the 'regulatory advantage' (RA) model. The comparison of both models allows testable predictions. We focus on the animal evolution because of the appearance of higher regulatory level (nervous system), which is absent in other lineages, and relevance to humans (including biomedical aspects).

Blind alleys and fruitful pathways in the comparative study of cultural cognition

A mere few decades ago, culture was thought a unique human attribute. Evidence to the contrary accumulated through the latter part of the twentieth century and has exploded in the present one, demonstrating the transmission of traditions through social learning across all principal vertebrate taxa and even invertebrates, notably insects. The scope of human culture is nevertheless highly distinctive. What makes our cultural capacities and their cognitive underpinnings so different? In this article I argue that in behavioural scientists' endeavours to answer this question, fruitful research pathways and their ensuing discoveries have come to exist alongside popular, yet in the light of current empirical evidence, highly questionable scenarios and even scientific blind alleys. I particularly re-evaluate theories that rely on the centrality of a supposed uniquely human capacity for imitative copying in explaining the distinctive capacity for massive cumulative cultural evolution (CCE) in our species. The most extreme versions of this perspective suffer logical incoherence and severe limits on scientific testability. By contrast the field has generated a range of rigorous observational and experimental methodologies that have revealed both long-term cultural fidelity and limited forms of CCE in non-human species. Attention now turns to directly investigating the scope, limits and underlying cognition of non-human versus human CCE, with a broader approach to factors additional to cultural transmission, notably the role of invention, innovation and evolved motivational biases underlying the scope of CCE in the species studied.

Authority matters: propaganda and the coevolution of behaviour and attitudes

Human decision-making is controlled by various factors including material cost-benefit considerations, values and beliefs, social influences, cognitive factors and errors. Among social influences, those by external authorities (e.g. educational, cultural, religious, political, administrative, etc.) are particularly important owing to their potential reach and power. To better understand the effects of 'soft' power of authorities we develop a unifying theoretical framework integrating material, cognitive and social forces controlling the joint dynamics of individual actions and beliefs. We apply our approach to three different phenomena: evolution of food sharing in small-scale societies, participation in political protests and effects of priming social identity in behavioural experiments. For each of these applications, we show that our approach leads to different (or simpler) explanations of human behaviour than alternatives. We highlight the type of measurements which can be helpful in developing practical applications of our approach. We identify and explicitly characterise the degree of mismatch between individual actions and attitudes. We assert that the effects of external authorities, of changing beliefs and of differences between people must be studied empirically, included in mathematical models, and accounted for when developing different policies aiming to modify or sustain human behaviour.

Reading emotions in Dogs' eyes and Dogs' faces

Our primary goal was to investigate human ability to recognize basic emotions from only the eyes of dogs in comparison to the whole face. Simultaneously, we replicated and extended previous research (Bloom et al., 2021), while validating American canine emotional facial expression photographs cross-culturally to Brazil. Participants (N = 120) viewed behaviorally-anchored photographs of three breeds. Half the participants in each condition (faces or eyes-only) viewed two-word forced choice items while the other half viewed four-word forced choice items. Participants identified target emotions from images of both dogs' faces and eyes-only at a higher rate than chance. Fear was accurately recognized more than the other emotions. When dogs are afraid, they open their eyes and expose the sclera, a conspicuous signal. Emotion identification accuracy was highest for the Rhodesian Ridgeback, who is similar in morphology to common Brazilian stray dogs (Vira-Latas Carmelo). We conjectured that Brazilians were more accustomed to seeing dogs with the Rhodesian Ridgeback morphology than the erect-eared breeds, thus increasing accuracy for this breed. Further studies with additional dog morphologies are desirable. In addition to research interest, our Canine Eyes task has the potential to become a test of individual differences in Theory of Mind with clinical applications.

Variations in limited resources allocation towards friends and strangers in children and adolescents from seven economically and culturally diverse societies

Humans are unique among primates in altruism and sharing limited recourses towards non-kin. Our study revealed the differences in proportions of individuals ready to share limited resources with virtual friend compared to virtual stranger in children and adolescents from seven ethnic groups, represented by four traditional rural African societies from Tanzania with different types of economy and three societies from Russia. The study was conducted between 2015 and 2020, and the data on 2253 individuals (1104 males and 1149 females) were obtained. Six economic games with limited resource allocations were conducted: Prosocial, Envy, and Sharing games with imagined friends and stranger partners accordingly. All players were later classified according to their decisions in all six games into four behavioral types: egoistic, egalitarian, altruistic, and mixed. The effects of population origin, gender, age, and stranger/friend type of interaction on the behavior were estimated by multinomial logistic regression. It was demonstrated that more respondents prefer altruistic and egalitarian behavior than egoistic and mixed in the whole sample. However, significant parochial effect was found. The study revealed significant main effects of ethnicity, age, and the interaction effects of ethnicity and parochial tendencies, and ethnicity and age on the behavior of players.

Runaway Social Selection in Human Evolution

Darwin posited that social competition among conspecifics could be a powerful selective pressure. Alexander proposed a model of human evolution involving a runaway process of social competition based on Darwin’s insight. Here we briefly review Alexander’s logic, and then expand upon his model by elucidating six core arenas of social selection that involve runaway, positive-feedback processes, and that were likely involved in the evolution of the remarkable combination of adaptations in humans. We discuss how these ideas fit with the hypothesis that a key life history innovation that opened the door to runaway social selection, and cumulative culture, during hominin evolution was increased cooperation among individuals in small fission-fusion groups.

The spread of technological innovations: effects of psychology, culture and policy interventions

Technological innovations drive the evolution of human societies. The success of innovations depends not only on their actual benefits but also on how potential adopters perceive them and how their beliefs are affected by their social and cultural environment. To deepen our understanding of socio-psychological processes affecting the new technology spread, we model the joint dynamics of three interlinked processes: individual learning and mastering the new technology, changes in individual attitudes towards it, and changes in individual adoption decisions. We assume that the new technology can potentially lead to a higher benefit but achieving it requires learning. We posit that individual decision-making process as well as their attitudes are affected by cognitive dissonance and conformity with peers and an external authority. Individuals vary in different psychological characteristics and in their attitudes. We investigate both transient dynamics and long-term equilibria observed in our model. We show that early adopters are usually individuals who are characterized by low cognitive dissonance and low conformity with peers but are sensitive to the effort of an external authority promoting the innovation. We examine the effectiveness of five different intervention strategies aiming to promote the diffusion of a new technology: training individuals, providing subsidies for early adopters, increasing the visibility of peer actions, simplifying the exchange of opinions between people, and increasing the effort of an external authority. We also discuss the effects of culture on the spread of innovations. Finally, we demonstrate that neglecting the cognitive forces and the dynamic nature of individual attitudes can lead to wrong conclusions about adoption of innovations. Our results can be useful in developing more efficient policies aiming to promote the spread of new technologies in different societies, cultures and countries.

Evolved Features of Artistic Motivation: Analyzing a Brazilian Database Spanning Three Decades

Darwin explored the evolutionary processes underlying artistic propensities in humans. He stressed the universality of the human mind by pointing to the shared pleasure which all populations take in dancing, engaging in music, acting, painting, tattooing, and self-decorating. Artistic motivation drives/reinforces individuals to engage in aesthetically oriented activities. As curiosity/play, artistic behavior is hypothesized as a functionally autonomous activity motivated intrinsically through an evolved, specific, and stable aesthetic motivational system. The author tested whether artistic motivation is rather intrinsically sourced, domain-specific, and temporally stable using a large decades-long real-life public Brazilian database of university applications. In Study I, the author analyzed reasons for career-choice responded to by 403,832 late-adolescent applicants (48.84% women), between 1987 and 1998. In Study II, the author analyzed another career-choice reason question responded to by 1,703,916 late-adolescent applicants (51.02% women), between 1987 and 2020. Music, Dance, Scenic Arts, Visual Arts, and Literary Studies, in combination, presented a higher percentage of individuals reporting intrinsic factors (e.g., personal taste/aptitude/fulfillment) and the lower proportion reporting extrinsic motives (e.g., the influence of media/teacher/family, salary, social contribution/prestige) than other career groups. If artistic motivation were a recent by-product of general curiosity or status-seeking, artistic and non-artistic careers would not differ. Overall, intrinsic motives were 2.60–6.35 times higher than extrinsic factors; among artistic applicants’ were 10.81–28.38 times higher, suggesting domain-specificity. Intrinsic motivation did not differ among artistic careers and remained stable throughout the periods. Converging results corroborated a specific, stable, and intrinsically sourced artistic motivation consistent with its possible evolutionary origins.

Breast-Feeding from an Evolutionary Perspective

Lactation is the most critical period of mammal feeding given the compulsory dependence on milk of the offspring during a more or less extensive period following birth. This has also been the case for the human species until relatively recent times when heterologous milk processing has allowed the alternative of artificial lactation. The advantages and disadvantages of natural and artificial lactation (formula) have been widely discussed from the biological, psychological and cultural perspectives, without reaching a general agreement among the breastfeeding women themselves or among the health professionals concerned. On the subject of breastfeeding, the information available is enormous but as in other instances, the excess of it has often made it difficult to acquire objective knowledge on the matter that has hindered decision-making in specific circumstances. This situation is understandable given the diversity and the innumerable contingencies that the mother and health professionals must face in their natural and social (cultural) environments. To reduce these difficulties and taking into consideration the biological and cultural aspects involved in infant feeding, this article analyzes some aspects of the subject from the point of view of biological evolution as the mother-child dyad, mother-infant conflicts, in particular the conflict of weaning, late-onset primary lactase deficiency and the prevention from childhood of adult diseases. All of which allows to offer a testimony of gratitude and respect to women who have assumed the responsibility of breastfeeding their infants because without them the human species would not have existed.

Tempo and Mode in Cultural Macroevolution

Evolutionary scientists studying social and cultural evolution have proposed a multitude of mechanisms by which cultural change can be effected. In this article we discuss two influential ideas from the theory of biological evolution that can inform this debate: the contrast between the micro- and macro-evolution, and the distinction between the tempo and mode of evolution. We add the empirical depth to these ideas by summarizing recent results from the analyses of data on past societies in Seshat: Global History Databank. Our review of these results suggests that the tempo (rates of change, including their acceleration and deceleration) of cultural macroevolution is characterized by periods of apparent stasis interspersed by rapid change. Furthermore, when we focus on large-scale changes in cultural traits of whole groups, the most important macroevolutionary mode involves inter-polity interactions, including competition and warfare, but also cultural exchange and selective imitation; mechanisms that are key components of cultural multilevel selection (CMLS) theory.

Cellular and Molecular Mechanisms Linking Human Cortical Development and Evolution

The cerebral cortex is at the core of brain functions that are thought to be particularly developed in the human species. Human cortex specificities stem from divergent features of corticogenesis, leading to increased cortical size and complexity. Underlying cellular mechanisms include prolonged patterns of neuronal generation and maturation, as well as the amplification of specific types of stem/progenitor cells. While the gene regulatory networks of corticogenesis appear to be largely conserved among all mammals including humans, they have evolved in primates, particularly in the human species, through the emergence of rapidly divergent transcriptional regulatory elements, as well as recently duplicated novel genes. These human-specific molecular features together control key cellular milestones of human corticogenesis and are often affected in neurodevelopmental disorders, thus linking human neural development, evolution, and diseases. Expected final online publication date for the Annual Review of Genetics, Volume 55 is November 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

The Role of the PFNA Operon of Bifidobacteria in the Recognition of Host's Immune Signals: Prospects for the Use of the FN3 Protein in the Treatment of COVID-19

Bifidobacteria are some of the major agents that shaped the immune system of many members of the animal kingdom during their evolution. Over recent years, the question of concrete mechanisms underlying the immunomodulatory properties of bifidobacteria has been addressed in both animal and human studies. A possible candidate for this role has been discovered recently. The PFNA cluster, consisting of five core genes, pkb2, fn3, aaa-atp, duf58, tgm, has been found in all gut-dwelling autochthonous bifidobacterial species of humans. The sensory region of the species-specific serine-threonine protein kinase (PKB2), the transmembrane region of the microbial transglutaminase (TGM), and the type-III fibronectin domain-containing protein (FN3) encoded by the I gene imply that the PFNA cluster might be implicated in the interaction between bacteria and the host immune system. Moreover, the FN3 protein encoded by one of the genes making up the PFNA cluster, contains domains and motifs of cytokine receptors capable of selectively binding TNF-α. The PFNA cluster could play an important role for sensing signals of the immune system. Among the practical implications of this finding is the creation of anti-inflammatory drugs aimed at alleviating cytokine storms, one of the dire consequences resulting from SARS-CoV-2 infection.

Coevolution of actions, personal norms and beliefs about others in social dilemmas

Human decision-making is affected by a diversity of factors including material cost-benefit considerations, normative and cultural influences, learning and conformity with peers and external authorities (e.g. cultural, religious, political, organisational). Also important are dynamically changing personal perceptions of the situation and beliefs about actions and expectations of others as well as psychological phenomena such as cognitive dissonance and social projection. To better understand these processes, I develop a unifying modelling framework describing the joint dynamics of actions and attitudes of individuals and their beliefs about the actions and attitudes of their groupmates. I consider which norms get internalised and which factors control beliefs about others. I predict that the long-term average characteristics of groups are largely determined by a balance between material payoffs and the values promoted by the external authority. Variation around these averages largely reflects variation in individual costs and benefits mediated by individual psychological characteristics. The efforts of an external authority to change the group behaviour in a certain direction can, counter-intuitively, have an opposite effect on individual behaviour. I consider how various factors can affect differences between groups and societies in the tightness/looseness of their social norms. I show that the most important factors are social heterogeneity, societal threat, effects of authority, cultural variation in the degree of collectivism/individualism, the population size and the subsistence style. My results can be useful for achieving a better understanding of human social behaviour and historical and current social processes, and in developing more efficient policies aiming to modify social behaviour.