drghirlanda

Computational behavior theory and cultural evolution

Category Archives: Science

Video: Pete Richerson, How Possibly Language Evolved

Part of the Cultural Evolution Seminar Series at Brooklyn College

(Download video, 620 MB)

Abstract: Human language has no close parallels in other systems of animal communication. Yet it is an important part of the cultural adaptation that serves to make humans an exceedingly successful species. Evolutionary scholars have have converged on the idea that the cultural and innate aspects of language were tightly linked in a process of gene-culture coevolution. They differ widely about the details of the process, particularly over the division of labor between genes and culture in the coevolutionary process. Why is language restricted to humans given that communication seems to be so useful? A plausible answer is that language is part of human cooperation. Why did the coevolutionary process come to rest leaving impressive cultural diversity in human languages? A plausible answer is that language diversity functions to limit communication between people who cannot freely trust one another or where even truthful communications from others would result in maladaptive behavior on the part of listeners.

Pete Richerson‘s primary research for many years has focused on the phenomena of cultural transmission of information and the evolutionary phenomena that derive from cultural transmission. He has been especially interested in the trade-offs involved in using other people as a source of information. Even if we imagine that the cultural system of humans has been adaptively optimized by natural selection, maladaptive cultural variants can still evolve. People cannot take advantage of normally adaptive rules like “imitate the successful” without incurring the risk that the appearance of success is a sham behind which lurks a culturally transmissible pathology. Prof. Richerson has investigated such processes with mathematical models, laboratory experiments, and most recently field investigations.

Video: Alex Mesoudi, The Experimental Study of Human Cultural Evolution

Part of the Cultural Evolution Seminar Series at Brooklyn College

(Download video, 580 MB)

Abstract: A growing body of theory has begun to analyse human culture – the body of beliefs, skills, knowledge, customs, attitudes and norms that is transmitted from individual to individual via social learning – as a Darwinian evolutionary process. Just as the biological evolution of species can be characterised as a Darwinian process of variation, selection and inheritance, so too culture exhibits these basic Darwinian properties. I will present the results of a series of experiments that have simulated cultural evolution in the lab using methods from social psychology. One set of studies using the “transmission chain method” have identified a bias in cultural evolution for information concerning social interactions over non-social interactions, as predicted by the “social brain” theory of human intelligence. Another set of studies have simulated the cultural evolution of prehistoric arrowhead designs, testing hypotheses that different patterns of arrowhead variation are caused by different ways in which arrowhead designs were transmitted between prehistoric hunter-gatherers.

Alex Mesoudi is Reader of Psychology at Queen Mary College, University of London. He is a psychologist who studies cultural evolution as a Darwinian evolutionary process, similar in key respects to the evolution of biological species. Culture can consequently be studied using similar methods, concepts and tools that biologists use to study biological (gene-based) evolution. My own research uses a combination of laboratory experiments and theoretical models to simulate the processes of cultural evolution, with the aim of identifying the small-scale, individual-level cultural  processes that generate the patterns and trends that are observed in human culture.

Video: Alberto Bisin, The economics of cultural transmission and socialization

Part of the Cultural Evolution Seminar Series at Brooklyn College

(Download video, 520 MB)

Abstract: Parents often spend considerable energy in teaching children their own beliefs, a behavior that has both economical and cultural underpinnings. I will present an economic analysis that predicts that minority groups spend more effort in teaching their children, and I will apply it to empirical data on marriage patterns. The analysis predicts that individuals from smaller groups most often choose to marry within their own group, and spend more resources in transmitting their beliefs to offspring.

Alberto Bisin is Professor in the Department of Economics at NYU. He is an economist interested in the interaction between cultural and socio-economic forces, expanding economic theory that has traditionally explained human behavior as determined by cost-benefit analyses independent of one’s cultural background.

Video: Stefano Adamo, The Social Diffusion of Specialist Knowledge

Part of the Cultural Evolution Seminar Series at Brooklyn College

(Download video, 660 MB)

Abstract: I argue that the social diffusion of specialist knowledge is contingent upon a combination of environmental and cognitive factors that make such ideas significant to the lay person and motivates their social transmission and retention. The same combination of factors, however, also engenders an incomplete comprehension of the ideas being spread. I propose a qualitative method to understand what makes specialist knowledge relevant and anticipate how lay peoplemay retain and spread such knowledge.

Stefano Adamo is Reader in Italian History and Culture at the University of Banja Luka, Bosnia Herzegovina, and fellowat the International Center of Economic Research, Turin, Italy. His research interests include the history of ideas and the cognitive theory of culture,especially the history of economic concepts (money, market, etc.) and their social diffusion.

Getting emotional for animal emotions

Do animals have emotions? This is tough philosophical question – how would we ever know? How do you even know I have emotions? Traditionally, we have recognized emotions by their outward manifestations alone. We see someone laugh and we assume they must be happy because we laugh when we are happy.  In the case of animals, relying on such inferences means that it is easier for us to attribute emotions to animals that are similar to ourselves, such as apes and monkeys, than to animals such as chickens, who show no facial expressions and whose behavior can be interpreted reliably only by experts.

There are other ways to infer emotions, for sure. When we see someone offering help, we usually assume they care for others. A recent report shows that chickens care for others, too. Hens react with distress calls and accelerated heart rate to their chickens being distressed by puffs of air. Is mother hen feeling bad for the chicks? We cannot know, but we should not just assume they can or cannot based on what we see and how we like them. We need to understand what emotions are and what a brain needs to generate feelings and consciousness. Today, we simply don’t know.

We should not be surprised however, that mothers in species with parental care show outward signs of emotions. The mother is there to nurture offspring, and she must react to potentially threatening situations. The outward signs of emotions we can measure are simply these defense mechanisms: the mother’s call tells both the chicks and potential predators that she is there, and her increased heart rate is a sign that she is getting ready to defend the chicks.

If we were to take these behaviors at face value as signs of feelings such as empathy for others, we would conclude that ants and bees are more empathic than chickens, than apes, than humans. Ants and bees do no hesitate to get killed to defend their nests, for example, and they do so with unerring resolution unknown to us, apes, or chickens. These behaviors are probably just genetically programmed reactions and we do not routinely assume that ants and bees feel bad for the eggs and larvae that are in danger when the nest is attacked. Konrad Lorenz pointed out in 1935 that the situation is quite complex:

“The Jackdaw (Coloeus monedula) possesses  a  very interesting reaction of defending any  fellow-member of the species in the grip of some bird or animal of prey.  For a long time I  have been familiar with the fact that my tame but free-living Jackdaws would furiously attack me if I  gripped one of them in my hand, but I  was very much astonished when I  inadvertently elicited exactly the same response by carrying a wet, black bathing-suit in my hand.  Subsequent experiments showed that  anything glistening black and dangling, carried by any living creature would release the very same reaction in the Jackdaws. Even Jackdaws themselves were subject to attack from their fellows when they happened to carry nesting material possessing  the characteristics just mentioned.”

To summarize: We cannot know what a hen, a bee, or any other organism feels because we do not understand how brains can produce feelings, and any appearance of feeling can be mimicked by the notorious mindless zombie of consciousness philosophy.

New Website on Sexual Preferences

The Internet Sex Survey Initiative (ISSI) has a new website. ISSI, of which I have been part since its inception in 2006, uses the Internet as a data source to understand sexual preferences and sexual development. So far, we have published the results of three surveys on sexual preferences, finding evidence for a critical age window during which preferences appear to develop, as well as for the influence of mother and father on sexual preferences.

Video: Laura Fortunato, The Evolution of Marriage and Kinship Systems

Part of the Cultural Evolution Seminar Series at Brooklyn College

Download video (500MB)

Abstract: Kinship and marriage systems represent the ways in which humans organize relatedness and reproduction. The work presented in this talk extends the philosophical, theoretical, and methodological foundations of evolutionary biology to the study of these aspects of human social behavior. Specifically, I use game theory to show that the evolution of monogamous marriage can be understood based on inclusive fitness theory. Results show that where resources are transferred across generations, monogamous marriage can be advantageous if partitioning of resources among the offspring of multiple wives causes a depletion of their fitness value, and/or if females grant husbands higher fidelity in exchange for exclusive investment of resources in their offspring. I evaluate the results of the model using evidence about the history and cross-cultural distribution of marriage and inheritance strategies. This suggests that monogamous marriage may have emerged in Eurasia following the adoption of intensive agriculture, as ownership of land became critical to productive and reproductive success.

Laura Fortunato is Omidyar Fellow at the Santa Fe Institute. Her research investigates theevolution of human social organization, focusing on the social norms regulating kinship and marriage. This involves understanding (i) why societies differ withrespect to these norms – for example, why some prescribe monogamous marriage, while the majority allow polygyny; and (ii) how this variation came about – forexample, whether the prevalence of monogamous marriage among European societies is simply an artefact of history, or whether itreflects ecological and/or social determinants.

Video: Aaron Kozbelt, The Evolution of the Creative Process

Part of the Cultural Evolution Seminar Series at Brooklyn College

Download Video (360MB)

Abstract: Much human cultural evolution stems from the creative innovations of individual persons, whose novel ideas or productions are valued and propagated by society. In this talk, I first describe the nature of the creative process as it is understood by psychologists. Next, to understand how the creative process impacts cultural evolution, I examine the possibility that the creative process itself is not historically invariant, but rather that it evolves over time. In elaborating this idea, I apply two biological frameworks: the ‘evolution of evolvability,’ whereby the evolutionary process itself becomes better at evolving over time, and ‘ontogenetic heterochrony,’ whereby small changes in the timing of developmental events can lead to profound morphological novelty. The application of these frameworks to human creativity provides a unified framework for understanding creativity, as well as informing cultural evolution – past, present, and future.

Aaron Kozbelt is Professor of Psychology at Brooklyn College, CUNY. His research program, focusing on creativity and cognition in the arts, derives largely from his outside interests. In addition to his training in psychology, he has spent more than 20 years as a practicing visual artist, and his initial research forays grew directly out of his experiences as an artist. Kozbelt has also incorporated his long-standing interest in classical music into a line of archival research examining patterns of creativity over the lifespan of classical composers. More recently, he has started research on creative cognition, humor production and sexual selection, and metacognition and evaluation in creative problem solving.

Video: R. Alex Bentley, Social Influence and Drift in Collective Behavior

Part of the Cultural Evolution Seminar Series at Brooklyn College

Download Video (500MB)

Abstract: Human decision models often begin with individual, cost-benefit analyses as the basic behavior, with any social influence as a secondary add-on. Thisoften underestimates social influence among humans, whose brains have actually evolved to handle social relations. In fact, a better starting point in many casesmay be to assume that people base their choices (consciously or not) primarily on the decisions of those around them. As captured by experiments and simpleevolutionary drift models, undirected social influence introduces an irrationality and unpredictability to collective behavior, with implications for anthropology,psychology and economics.

Alex Bentley is Reader in Anthropology at Durham University, where he is co-founder of the Centre for the Coevolution of Biologyand Culture, and Deputy Director of a 5 year project on ‘Tipping Points: Mathematics, Metaphors and Meanings”, funded by theLeverhulme Trust.

Confidence Intervals

I have not found an accepted way to write asymmetrical confidence intervals. Two possibilities are rendered in the image below. I personally prefer the second one, which uses the standard ± sign already in use for symmetrical confidence intervals, simply splitting the confidence interval boundaries into two stacked numbers.

Another possibility is to write directly the upper and lower limits: