Drift as a Driver of Language Change: An Artificial Language Experiment.

Over half a century ago, George Zipf observed that more frequent words tend to be older. Corpus studies since then have confirmed this pattern, with more frequent words being replaced and regularized less often than less frequent words. Two main hypotheses have been proposed to explain this: that frequent words change less because selection against innovation is stronger at higher frequencies, or that they change less because stochastic drift is stronger at lower frequencies. Here, we report the first experimental test of these hypotheses. Participants were tasked with learning a miniature language consisting of two nouns and two plural markers. Nouns occurred at different frequencies and were subjected to treatments that varied drift and selection. Using a model that accounts for participant heterogeneity, we measured the rate of noun regularization, the strength of selection, and the strength of drift in participant responses. Results suggest that drift alone is sufficient to generate the elevated rate of regularization we observed in low-frequency nouns, adding to a growing body of evidence that drift may be a major driver of language change.

Cultural Evolution and Digital Media: Diffusion of Fake News About COVID-19 on Twitter.

Disinformation (fake news) is a major problem that affects modern populations, especially in an era when information can be spread from one corner of the world to another in just one click. The diffusion of misinformation becomes more problematic when it addresses issues related to health, as it can affect people at both the individual and population levels. Through the ideas proposed by cultural evolution theory, in this study, we seek to understand the dynamics of disseminating messages (cultural traits) with untrue content (maladaptive traits). For our investigation, we used the scenario caused by the Coronavirus Disease 2019 (COVID-19) pandemic as a model. The instability caused by the pandemic provides a good model for the study of adapted and maladaptive traits, as the information can directly affect individual and population fitness. Through data collected on the Twitter platform (259,176 tweets) and using machine learning techniques and web scraping, we built a predictive model to analyze the following questions: (1) Is false information more shared? (2) Is false information more adopted? (3) Do people with social prestige influence the dissemination of maladaptive traits of COVID-19? We observed that fake news features contained in messages with false information were shared and adopted as unblemished messages. We also observed that social prestige was not a determining factor for the diffusion of maladaptive traits. Even with the ability to allow connections between individuals participating in social media, some factors such as attachment to cultural traits and the formation of social bubbles can favor isolation and decrease connectivity between individuals. Consequently, in the scenario of isolation between groups and low connectivity between individuals, there is a reduction in cultural exchange between people, which interferes with the dynamics of the selection of cultural traits. Thus, maladaptive (harmful) traits are favored and maintained in the cultural system. We also argue that the local Brazilian cultural context can be a determining factor for maintaining maladaptive traits. We conclude that in an unstable (pandemic) scenario, the information transmitted on Twitter is not reliable in relation to the increase in fitness, which may occur because of the low cultural exchange promoted by the personalization of the social network and cultural context of the population. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s42979-021-00836-w.

Cultural selection and biased transformation: two dynamics of cultural evolution.

Here, I discuss two broad versions of human cultural evolution which currently exist in the literature and which emphasize different underlying dynamics. One, which originates in population-genetic-style modelling, emphasizes how cultural selection causes some cultural variants to be favoured and gradually increase in frequency over others. The other, which draws more from cognitive science, holds that cultural change is driven by the biased transformation of cultural variants by individuals in non-random and consistent directions. Despite claims that cultural evolution is characterized by one or the other of these dynamics, these are neither mutually exclusive nor a dichotomy. Different domains of human culture are likely to be more or less strongly weighted towards cultural selection or biased transformation. Identifying cultural dynamics in real-world cultural data is challenging given that they can generate the same population-level patterns, such as directional change or cross-cultural stability, and the same cognitive and emotional mechanisms may underlie both cultural selection and biased transformation. Nevertheless, fine-grained historical analysis and laboratory experiments, combined with formal models to generate quantitative predictions, offer the best way of distinguishing them. This article is part of the theme issue 'Foundations of cultural evolution'.

Modelling cultural systems and selective filters.

A specific goal of the field of cultural evolution is to understand how processes of transmission and selection at the individual level lead to population-wide patterns of cultural diversity and change. Models of cultural evolution have typically assumed that traits are independent of one another and essentially exchangeable. But culture has a structure: traits bear relationships to one another that affect the transmission and selection process itself. Here, we introduce a modelling framework to explore the effect of interdependencies on the process of learning. Through simulations, we find that introducing a simple structure changes the cultural dynamics. Based on a basic filtering mechanism for parsing trait relationships, more elaborate cultural filters emerge. In a mostly incompatible cultural domain of traits, these filters organize culture into mostly (but not fully) consistent and stable systems. Incompatible domains produce small homogeneous cultures, while more compatibility increases size, diversity and group divergence. When individuals copy based on a trait's features (here, its compatibility relationships), they produce more homogeneous cultures than when they copy based on the agent carrying the cultural trait. We discuss the implications of considering cultural systems and filters in the dynamics of cultural change. This article is part of the theme issue 'Foundations of cultural evolution'.

Population turnover facilitates cultural selection for efficiency in birds.

Culture, defined as socially transmitted information and behaviors that are shared in groups and persist over time, is increasingly accepted to occur across a wide range of taxa and behavioral domains.1 While persistent, cultural traits are not necessarily static, and their distribution can change in frequency and type in response to selective pressures, analogous to that of genetic alleles. This has led to the treatment of culture as an evolutionary process, with cultural evolutionary theory arguing that culture exhibits the three fundamental components of Darwinian evolution: variation, competition, and inheritance.2-5 Selection for more efficient behaviors over alternatives is a crucial component of cumulative cultural evolution,6 yet our understanding of how and when such cultural selection occurs in non-human animals is limited. We performed a cultural diffusion experiment using 18 captive populations of wild-caught great tits (Parus major) to ask whether more efficient foraging traditions are selected for, and whether this process is affected by a fundamental demographic process-population turnover. Our results showed that gradual replacement of individuals with naive immigrants greatly increased the probability that a more efficient behavior invaded a population's cultural repertoire and outcompeted an established inefficient behavior. Fine-scale, automated behavioral tracking revealed that turnover did not increase innovation rates, but instead acted on adoption rates, as immigrants disproportionately sampled novel, efficient behaviors relative to available social information. These results provide strong evidence for cultural selection for efficiency in animals, and highlight the mechanism that links population turnover to this process.

The shortlist effect: nestedness contributions as a tool to explain cultural success.

Detecting the forces behind the success or failure of cultural products, such as books or films, remains a challenge. Three such forces are drift, context-biased selection and selection based on content - when things succeed because of their intrinsic appeal. We propose a tool to study content-biased selection in sets of cultural collections - e.g. libraries or movie collections - based on the 'shortlist effect': the fact that smaller collections are more selective and more likely to favour highly appealing items over others. We use a model to show that, when the shortlist effect is at work, content-biased cultural selection is associated with greater nestedness in sets of collections. Having established empirically the existence of the shortlist effect, and of content-biased selection, in 28 sets of movie collections, we show that nestedness contributions can be used to estimate to what extent specific movies owe their success to their intrinsic properties. This method can be used in a wide range of datasets to detect the items that owe their success to their intrinsic appeal, as opposed to 'hidden gems' or 'accidental hits'.

Efeitos de um Análogo de Reforçamento Negativo sobre a Seleção de Culturantes / Effects of an Analogue of Negative Reinforcement on the Selection of Culturants

Resumo O presente estudo investigou os efeitos de um análogo de reforçamento negativo sobre a seleção de culturantes e, diferentemente de estudos anteriores, buscou eliminar a interferência da punição negativa de outros culturantes. Três microculturas de laboratório, com três participantes cada, foram expostas a um delineamento ABAB. Os participantes escolhiam entre linhas coloridas e numeradas de 1 a 10. Na condição de Reforçamento Positivo (A), os culturantes-alvo produziam consequências culturais. Na condição de Reforçamento Negativo (B), as consequências culturais eram subtraídas a cada 30s, mas os culturantes-alvo podiam adiar a perda dessas consequências. O análogo de reforçamento negativo, assim como o de reforçamento positivo, selecionou os culturantes-alvo sem a interferência de contingências punitivas acidentais.

Abstract The present research investigated the effect of a negative reinforcement analog on the selection of culturants and, unlike previous studies, sought to eliminate the interference of the negative punishment of other culturants. Three laboratory microcultures, with three participants in each of them, were exposed to an ABAB design. The participants chose between colored lines, numbered from 1 to 10. In the Positive Reinforcement condition (A), target culturants produced cultural consequences. In the Negative Reinforcement condition (B), cultural consequences were subtracted every 30 seconds, but target culturants could delay the loss of those consequences. The analog of negative reinforcement, as well as that of positive reinforcement, selected target culturants without the interference of accidental punitive contingencies.

Modelling cultural selection on biological fitness to integrate social transmission and adaptive explanations for human behaviour.

One of the difficulties with cultural group selection theory highlighted in the review by Smith (2020, Evol. Hum. Sci., 2, e7) is its inability to separate the evolutionary effects of selection of cultural traits based on biological fitness (Cultural Selection 1) from the effects of selection based on cultural fitness (Cultural Selection 2). Confusing these two processes can hinder the integration of adaptive explanations for human behaviour, which focus on biological fitness, and cultural evolution explanations, which often focus on social transmission. Recent empirical work is starting to bridge this gap, but progress in mathematical modelling has been considerably slower. Here, I suggest that modellers can contribute to achieving this integration by further developing models of Cultural Selection 1, where behaviours are influenced by culturally inherited traits selected on the basis of their effects on biological fitness. These models should build on existing social evolution theory methods and replace genetic relatedness with cultural relatedness, that is the probability that two individuals share a cultural variant.

Alteration of flavonoid pigmentation patterns during domestication of food crops.

Flavonoids are plant pigments that provide health benefits for human and animal consumers. Understanding why domesticated crops have altered pigmentation patterns and unraveling the molecular/genetic mechanisms that underlie this will facilitate the breeding of new (healthier) varieties. We present an overview of changes in flavonoid pigmentation patterns that have occurred during crop domestication and, where possible, link them to the molecular changes that brought about the new phenotypes. We consider species that lost flavonoid pigmentation in the edible part of the plant at some point during domestication (like cereals). We also consider the converse situation, for example eggplant (aubergine), which instead gained strong anthocyanin accumulation in the skin of the fruit during domestication, and some varieties of citrus and apple that acquired anthocyanins in the fruit flesh. Interestingly, the genes responsible for such changes are sometimes closely linked to, or have pleiotropic effects on, important domestication genes, suggesting accidental and perhaps inevitable changes of anthocyanin patterning during domestication. In other cases, flavonoid pigmentation patterns in domesticated crops are the result of cultural preferences, with examples being found in varieties of citrus, barley, wheat, and maize. Finally, and more recently, in some species, anthocyanins seem to have been the direct target of selection in a second wave of domestication that followed the introduction of industrial food processing.

Culturo-behavioral Hypercycles and the Metacontingency: Incorporating Self-Organizing Dynamics into an Expanded Model of Cultural Change.

Selection by consequences is a causal mode that operates across multiple levels of analysis including in biological organisms via natural selection, and at the levels of individual (via operant contingencies) and cultural behaviors (Skinner, 1953, Science, 213, 501-504, 1981, 1988, 1989; Glenn in The Behavior Analyst, 11(2), 161-179, 1988, The Behavior Analyst, 27(2), 133-151, 2004). The common dynamics of systems within which selection by consequences operates has led to attempts to develop an interdisciplinary understanding of adaptation. The metacontingency (Glenn in The Behavior Analyst, 11(2), 161-179, 1988, The Behavior Analyst, 27(2), 133-151, 2004) has been proposed as a process of cultural-level selection, but this proposal has been challenged in several critiques. First, several theorists have suggested that the metacontingency addresses within-groups processes of selection that have already been addressed by more parsimonious theories. Second, principles of self-organizing systems, should they apply within cultural settings, may significantly limit the efficacy of the metacontingency as a construct of cultural analysis. More recently, additional processes of selection, the selection of cultures and cultural selection (Couto & Sandaker in Behavior & Social Issues, 25, 54-60, 2016) have been suggested as between-groups processes of selection, operating at a level higher than operant selection, and fulfilling the role of cultural-level selection as proposed by Skinner. In the present article, these new processes will be considered in light of principles of self-organization and the conditions within which self-organization may occur. The culturant hypercycle, the operant hypercycle, and interactions between the two (culturo-behavioral hypercycles) are defined as self-organizing processes that help to explain how the selection of cultures and cultural selection may occur. Further, the theory of self-organizing systems is used to explain how self-organizing dynamics may emerge via metacontingencies, reintegrating the culturant and metacontingent selection into an expanded model explaining processes of cultural evolution.

Acoustic adaptation to city noise through vocal learning by a songbird.

Anthropogenic noise imposes novel selection pressures, especially on species that communicate acoustically. Many animals-including insects, frogs, whales and birds-produce sounds at higher frequencies in areas with low-frequency noise pollution. Although there is support for animals changing their vocalizations in real time in response to noise (i.e. immediate flexibility), other evolutionary mechanisms for animals that learn their vocalizations remain largely unexplored. We hypothesize that cultural selection for signal structures less masked by noise is a mechanism of acoustic adaptation to anthropogenic noise. We test this hypothesis by presenting nestling white-crowned sparrows (Zonotrichia leucophyrs) with less-masked (higher-frequency) and more-masked (lower-frequency) tutor songs either during playback of anthropogenic noise (noise-tutored treatment) or at a different time from noise playback (control treatment). As predicted, we find that noise-tutored males learn less-masked songs significantly more often, whereas control males show no copying preference, providing strong experimental support for cultural selection in response to anthropogenic noise. Further, noise-tutored males reproduce songs at higher frequencies than their tutor, indicating a distinct mechanism to increase signal transmission in a noisy environment. Notably, noise-tutored males achieve lower performance songs than their tutors, suggesting potential costs in a sexual selection framework.

Designing cultural multilevel selection research for sustainability science.

Humans stand out among animals in that we cooperate in large groups to exploit natural resources, and accumulate resource exploitation techniques across generations via cultural learning. This uniquely human form of adaptability is in large part to blame for the global sustainability crisis. This paper builds on cultural evolutionary theory to conceptualize and study environmental resource use and overexploitation. Human social learning and cooperation, particularly regarding social dilemmas, result in both sustainability crises and solutions. Examples include the collapse of global fisheries, and multilateral agreements to halt ozone depletion. We propose an explicitly evolutionary approach to study how crises and solutions may emerge, persist, or disappear. We first present a brief primer on cultural evolution to define group-level cultural adaptations for resource use. This includes criteria for identifying where group-level cultural adaptations may exist, and if a cultural evolutionary approach can be implemented in studying a given system. We then outline a step-by-step process for designing a study of group-level cultural adaptation, including the major methodological considerations that researchers should address in study design, such as tradeoffs between validity and control, issues of time scale, and the value of both qualitative and quantitative data and analysis. We discuss how to evaluate multiple types of evidence synthetically, including historical accounts, new and existing data sets, case studies, and simulations. The electronic supplement provides a tutorial and simple computer code in the R environment to lead users from theory to data to an illustration of an empirical test for group-level adaptations in sustainability research.

Reasons to be fussy about cultural evolution.

This discussion paper responds to two recent articles in Biology and Philosophy that raise similar objections to cultural attraction theory, a research trend in cultural evolution putting special emphasis on the fact that human minds create and transform their culture. Both papers are sympathetic to this idea, yet both also regret a lack of consilience with Boyd, Richerson and Henrich's models of cultural evolution. I explain why cultural attraction theorists propose a different view on three points of concern for our critics. I start by detailing the claim that cultural transmission relies not chiefly on imitation or teaching, but on cognitive mechanisms like argumentation, ostensive communication, or selective trust, whose evolved or habitual function may not be the faithful reproduction of ideas or behaviours. Second, I explain why the distinction between context biases and content biases might not always be the best way to capture the interactions between culture and cognition. Lastly, I show that cultural attraction models cannot be reduced to a model of guided variation, which posits a clear separation between individual and social learning processes. With cultural attraction, the same cognitive mechanisms underlie both innovation and the preservation of traditions.

Human Phenotypic Diversity: An Evolutionary Perspective.

As humans migrated across the world, they encountered new environments requiring them to adapt to new challenges that presented themselves. The distribution of human phenotypes observed today is the result of this continuous adaptation, via biological/physiological and cultural means, and also by the modification of cultural practices, which leads to biological changes. In this chapter, we examine a number of adaptive traits and the roles played by their genetic and environmental determinants. We have selected a few traits used for human identification purposes (externally visible characteristics), associated with human metabolism and linked to a shift in subsistence method and food consumption. We discuss the evolutionary processes that have affected the temporal and spatial distribution of these traits, including natural, sexual, and cultural selection.

Metacontingência, dilema do prisioneiro e cooperação: efeitos da interação verbal e da forma de apresentação da consequência cultural / Metacontingency, prisoners dilemma, and cooperation: effects of verbal interaction and form of cultural consequence presentation

Em uma metacontingência, respostas de dois ou mais indivíduos interagindo (denominadas um culturante) produzem estímulos (denominados de consequências culturais) capazes de afetar a recorrências daquelas respostas. Resultados de experimentos sobre metacontingência têm sido tratados como demonstrações de um tipo de seleção cultural. Além de sugerir a importância de interações verbais entre participantes, alguns desses experimentos têm empregado tarefas baseadas no dilema do prisioneiro repetido (iterated prisoners dilemma, IPD) interpretando-o, porém, como a programação apenas de contingências operantes. O Experimento 1 avaliou se um IPD com mais de 200 tentativas produziria escolhas cooperativas simultâneas de modo fidedigno e se a interação verbal entre participantes aumentaria a cooperação. 4 quartetos de universitários utilizaram 4 computadores conectados em rede (sem contato visual) e foram expostos a condições com ou sem permissão para usar uma sala de bate-papo pelo computador (chat) em um delineamento de linhas de base múltiplas entre quartetos. Os resultados demonstraram claramente que escolhas cooperativas unânimes podem ocorrer fidedignamente em um IPD e que a interação verbal entre participantes aumenta rapidamente tais escolhas. Esses resultados destacam a semelhança entre estudos sobre IPD e sobre metacontingências, nos quais são programadas consequências para comportamentos inter-relacionados de vários indivíduos. No Experimento 2, uma consequência cultural foi sobreposta às consequências já programadas pelo IPD: os quartetos podiam produzir pontos iguais para todos os participantes (feedback do mercado) contingentes a diferentes números de escolhas cooperativas. Como no Experimento 1, condições nas quais o uso do chat eram ou não permitidos foram arranjadas em um delineamento de linhas de base múltiplas entre quartetos. A interação verbal promoveu rápida e marcadamente a seleção cultural pelo feedback do mercado. Um quarteto... (AU)

In a metacontingency, responses of two or more interacting individuals (a culturant) produce stimuli (called cultural consequences) that affect the recurrence of those responses. Results of metacontingency experiments are said to demonstrate a kind of cultural selection. Besides suggesting the importance of verbal interactions between participants, some of these experiments have used tasks based on the iterated prisoner's dilemma (IPD) interpreting it, however, as programming only operant contingencies. Experiment 1 examined whether an IPD with 200-plus trials would produce simultaneous cooperative choices reliably and whether verbal interaction between participants would increase cooperation. 4 quartets of undergraduate and graduate students used 4 networked computers (without visual contact), and were exposed to conditions with or without permission to use the computer chat room in a multiple baseline design between quartets. Results clearly demonstrate that unanimous cooperative choices can occur reliably in an IPD, and that verbal interaction between participants rapidly increases such choices. These results highlight the similarity between IPD and metacontingencies studies, both of which program consequences for inter-related behaviors of many individuals. In Experiment 2, a cultural consequence was superimposed on the consequences already programmed by the IPD: quartets could produce equal points for all participants (market feedback) contingent on different numbers of cooperative choices. As in Experiment 1, we arranged conditions in which chat use were or not allowed in a multiple baseline design between quartets. Verbal interaction quickly and markedly promoted cultural selection by the market feedback. One quartet presented some control of culturants by the market feedback before verbal interactions, but production of cultural consequences increased substantially after using the chat. Experiment 3 replicated Experiment 2 presenting the... (AU)

Ethnolinguistic structuring of sorghum genetic diversity in Africa and the role of local seed systems.

Sorghum is a drought-tolerant crop with a vital role in the livelihoods of millions of people in marginal areas. We examined genetic structure in this diverse crop in Africa. On the continent-wide scale, we identified three major sorghum populations (Central, Southern, and Northern) that are associated with the distribution of ethnolinguistic groups on the continent. The codistribution of the Central sorghum population and the Nilo-Saharan language family supports a proposed hypothesis about a close and causal relationship between the distribution of sorghum and languages in the region between the Chari and the Nile rivers. The Southern sorghum population is associated with the Bantu languages of the Niger-Congo language family, in agreement with the farming-language codispersal hypothesis as it has been related to the Bantu expansion. The Northern sorghum population is distributed across early Niger-Congo and Afro-Asiatic language family areas with dry agroclimatic conditions. At a finer geographic scale, the genetic substructure within the Central sorghum population is associated with language-group expansions within the Nilo-Saharan language family. A case study of the seed system of the Pari people, a Western-Nilotic ethnolinguistic group, provides a window into the social and cultural factors involved in generating and maintaining the continent-wide diversity patterns. The age-grade system, a cultural institution important for the expansive success of this ethnolinguistic group in the past, plays a central role in the management of sorghum landraces and continues to underpin the resilience of their traditional seed system.

Seleção de práticas culturais complexas: avaliação experimental de um análogo do procedimento de aproximação sucessiva / The selection of complex cultural practices: experimental assessment of an analogous of the successive approximation procedure

O processo de evolução cultural tem sido investigado experimentalmente na Análise do Comportamento com base no conceito de metacontingências, que descreve a relação funcional entre contingências comportamentais entrelaçadas (CCEs), seu produto agregado (PA) e consequências culturais (CCs) liberadas por um sistema receptor. Neste estudo, buscou-se investigar a possibilidade de selecionar um dado entrelaçamento (um padrão de comportamentos coordenados entre os membros de um grupo) com um análogo doprocedimento de aproximação sucessiva, usado na modelagem do comportamento individual. Dois grupos de quatro universitários foram expostos a procedimentos de aproximação sucessiva em arranjos de metacontingências. Os entrelaçamentos alvo tinham graus de complexidade quevariavam quanto ao número de exigências para a produção da CC (complexidade ambiental) e quanto ao número de membros do grupo (complexidade de componente). No Experimento 1, foi programado o aumento gradual da complexidade ambiental e, no Experimento 2, o aumento gradual e simultâneo de complexidade de componente e ambiental. A tarefa dos grupos consistiade escolher linhas em uma matriz de dez linhas de cinco cores diferentes, numeradas de 1 a 10, e dez colunas, nomeadas de A a J. Contingências individuais e contingências culturaisfuncionalmente independentes umas das outras foram programadas. Escolhas individuais de linhas ímpares produziam fichas trocáveis por dinheiro (consequência individual); escolhas delinhas com certas coordenações de cores produziam itens escolares para doação a uma escola pública (CCs). Os resultados do Experimento 1 (modelagem de CCEs com complexidade ambiental crescente) demonstraram a seleção de CCEs alvo. No Experimento 2, não houve seleção dos entrelaçamentos alvo. Esse resultado demonstra a possibilidade de modelagem de CCEscomplexas empregando-se o procedimento de aproximação sucessiva, ao mesmo tempo em quesugere que a progressão simultânea de várias dimensões da complexidade do entrelaçamento pode comprometer a eficácia do procedimento na produção de unidades culturais complexas. Todavia, certas características do preparo experimental empregado neste experimento sugerem que outras variáveis (notadamente, a alternância das funções dos membros do grupo) podem ter concorrido com o procedimento de aproximação sucessiva e afetado a sua eficácia.

Cultural evolution has been the subject matter of experimental investigation in Behavior Analysis, under the concept of metacontingency. Metacontingencies describe the functional relationship between interlocking behavioral contingencies (IBCs), their aggregateproduct (AP), and cultural consequences delivered by a receiving system. In this study, we investigated the selection of IBCs (a pattern of coordinated behaviors of the members of a group), employing an analog of the successive approximation procedure, employed in modelling individual behavior. Two groups, four undergraduate students in each, were exposed to a successive approximation procedure in a metacontingency setting. The target IBCs involved degrees of complexity that varied with respect to the requirements to produce the CC(environmental complexity), and to the number of group members (component complexity). In Experiment 1, a gradual increase in environmental complexity was programmed. In Experiment 2,there was a gradual and simultaneous increase in both component and environmental complexity. The task to be performed consisted of choosing rows in a 10x10 matrix, in whichrows were of five different colors, numbered from 1 to 10, and columns were named from A to J. Individual contingencies, as well as functionally independent cultural contingencies were programmed. Individual choices of odd rows produced tokens exchangeable for money(individual consequence); choices of rows of given coordinations of colors (IBCs+PAs) produced school itens to be later donated to a public school (CCs). Results of Experiment 1 (modelling ofIBCs with increasing environmental complexity) showed the selection of target IBCs. In Experiment 2, the target IBCs were not selected. These results show that the successive approximation procedure may be effective in the modelling of IBCs, and suggests, as well, that simutaneous progression of both environmental, and component complexity dimensions may affect the efficacy of the procedure in producing complex cultural units. However, some aspects of the experimental preparation employed in this study also suggest that other variables (namely, the changing functions of the group members) may have competed with the successiveapproximation procedure and affected its efficacy.

Seleção de práticas culturais complexas: avaliação experimental de um análogo do procedimento de aproximação sucessiva / The selection of complex cultural practices: experimental assessment of an analogous of the successive approximation procedure

O processo de evolução cultural tem sido investigado experimentalmente na Análise do Comportamento com base no conceito de metacontingências, que descreve a relação funcional entre contingências comportamentais entrelaçadas (CCEs), seu produto agregado (PA) e consequências culturais (CCs) liberadas por um sistema receptor. Neste estudo, buscou-se investigar a possibilidade de selecionar um dado entrelaçamento (um padrão de comportamentos coordenados entre os membros de um grupo) com um análogo doprocedimento de aproximação sucessiva, usado na modelagem do comportamento individual. Dois grupos de quatro universitários foram expostos a procedimentos de aproximação sucessiva em arranjos de metacontingências. Os entrelaçamentos alvo tinham graus de complexidade quevariavam quanto ao número de exigências para a produção da CC (complexidade ambiental) e quanto ao número de membros do grupo (complexidade de componente). No Experimento 1, foi programado o aumento gradual da complexidade ambiental e, no Experimento 2, o aumento gradual e simultâneo de complexidade de componente e ambiental. A tarefa dos grupos consistiade escolher linhas em uma matriz de dez linhas de cinco cores diferentes, numeradas de 1 a 10, e dez colunas, nomeadas de A a J. (AU)

Contingências individuais e contingências culturaisfuncionalmente independentes umas das outras foram programadas. Escolhas individuais de linhas ímpares produziam fichas trocáveis por dinheiro (consequência individual); escolhas delinhas com certas coordenações de cores produziam itens escolares para doação a uma escola pública (CCs). Os resultados do Experimento 1 (modelagem de CCEs com complexidade ambiental crescente) demonstraram a seleção de CCEs alvo. No Experimento 2, não houve seleção dos entrelaçamentos alvo. Esse resultado demonstra a possibilidade de modelagem de CCEscomplexas empregando-se o procedimento de aproximação sucessiva, ao mesmo tempo em quesugere que a progressão simultânea de várias dimensões da complexidade do entrelaçamento pode comprometer a eficácia do procedimento na produção de unidades culturais complexas. Todavia, certas características do preparo experimental empregado neste experimento sugerem que outras variáveis (notadamente, a alternância das funções dos membros do grupo) podem ter concorrido com o procedimento de aproximação sucessiva e afetado a sua eficácia. (AU)

Cultural evolution has been the subject matter of experimental investigation in Behavior Analysis, under the concept of metacontingency. Metacontingencies describe the functional relationship between interlocking behavioral contingencies (IBCs), their aggregateproduct (AP), and cultural consequences delivered by a receiving system. In this study, we investigated the selection of IBCs (a pattern of coordinated behaviors of the members of a group), employing an analog of the successive approximation procedure, employed in modelling individual behavior. Two groups, four undergraduate students in each, were exposed to a successive approximation procedure in a metacontingency setting. The target IBCs involved degrees of complexity that varied with respect to the requirements to produce the CC(environmental complexity), and to the number of group members (component complexity). In Experiment 1, a gradual increase in environmental complexity was programmed. In Experiment 2,there was a gradual and simultaneous increase in both component and environmental complexity. The task to be performed consisted of choosing rows in a 10x10 matrix, in whichrows were of five different colors, numbered from 1 to 10, and columns were named from A to J. (AU)

Individual contingencies, as well as functionally independent cultural contingencies were programmed. Individual choices of odd rows produced tokens exchangeable for money(individual consequence); choices of rows of given coordinations of colors (IBCs+PAs) produced school itens to be later donated to a public school (CCs). Results of Experiment 1 (modelling ofIBCs with increasing environmental complexity) showed the selection of target IBCs. In Experiment 2, the target IBCs were not selected. These results show that the successive approximation procedure may be effective in the modelling of IBCs, and suggests, as well, that simutaneous progression of both environmental, and component complexity dimensions may affect the efficacy of the procedure in producing complex cultural units. However, some aspects of the experimental preparation employed in this study also suggest that other variables (namely, the changing functions of the group members) may have competed with the successiveapproximation procedure and affected its efficacy. (AU)

The Selection Metaphor: The Concepts of Metacontingencies and Macrocontingencies Revisited / La metáfora de la selección: una revisión de los conceptos de metacontingencia y macrocontingencia

Las explicaciones tradicionales de la conducta cultural se fundamentan en una perspectiva seleccionista. Sin embargo, varias discusiones teóricas se han preguntado sobre la misma y sobre la identificación de unidades de selección. Argumentaré que, si bien las propuestas centrales de Glenn constituyen una extensión valiosa de los principios operantes, el enfoque seleccionista ha entorpecido el desarrollo conceptual y empírico de la teoría. Se presenta un examen de las nociones fundamentales de la teoría de la evolución cultural; específicamente, una revisión de los conceptos de metacontingencias, contingencias conductuales entrelazadas, macrocontingencias y productos agregados, en términos de su contribución a una explicación válida y significativa del comportamiento cultural. Se sugiere que se requieren análisis experimentales funcionales para identificar el control de la conducta por parte de contingencias individuales o grupales, incluyendo los productos acumulados y agregados.

Current mainstream accounts of cultural behavior are strongly founded on a selectionist perspective. However, more than a few theoretical discussions have emerged regarding the appropriateness of the subject matter and the identification of units of selection. I argue that although Glenn's central formulations constitute a valuable extension of operant principles, the selectionist approach has hindered the theory's conceptual and empirical development. An examination of the fundamental notions included in the theory of cultural evolution is presented. Specifically, we review the concepts of metacontingencies, interlocking behavioral contingencies, macrocontingencies, and aggregate products in terms of their contribution to a valid and significant account of cultural behavior. It is suggested that experimental functional analyses are required to identify control of behavior by local contingencies or group consequences including cumulative and aggregate products.

Metacontingencies, Cultural Selection and Social/Verbal / Metacontingencias, Selección Cultural y Ambiente Social/Verbal

Resumen En las últimas décadas, Sigrid Glenn, a partir de la proposición del concepto de 'metacontingencia', ha desarrollado una propuesta analítico-conductual que busca ampliar el tratamiento skinneriano de los procesos de selección/ evolución cultural. Este artículo presenta inicialmente una descripción del desarrollo conceptual de esta propuesta. A continuación, teniendo en cuenta la importancia que se le ha asignado a repertorios verbales en el proceso de selección cultural, se presentan las propuestas de los antropólogos Terrence Deacon y Marvis Harris que abordan la relación entre la evolución de ambientes sociales/verbales y la selección/evolución de prácticas culturales. Por último, basándose en estas propuestas, se discuten formas en que el control de la conducta individual por el grupo - y sus agencias de control - sugieren un creciente desarrollo de mecanismos de control verbal/social, lo que indica la importancia de fomentar el estudio de las relaciones entre la evolución de ambientes sociales/verbales y la selección/ evolución de prácticas culturales.

In the last decades, Sigrid Glenn, from the proposition of the concept of 'metacontingency', has developed a behavioral-analytic proposal that seeks to amplify the Skinnerian treatment given to cultural selection/evolution processes. This paper initially presents a description of the conceptual development of this proposal. Afterwards, considering the importance that has been assigned to verbal repertoire in the cultural selection process, proposals from anthropologists Terrence Deacon and Marvis Harris, who approach the relationship between the evolution of social/verbal environments and the selection/evolution of cultural practices, are presented. Finally, based on these propositions, forms in which the control of individual behavior by the group - and by their controlling agencies - seems to denote an increasing development in verbal/ social control mechanisms are discussed, indicating the importance to go more deeply into the study of relationships between the evolution of social/verbal environments and the selection/evolution of cultural practices.