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CONFERENCE ABSTRACTS:

Understanding Vision in Empirical Terms
Dale Purves, Neurobiology, Duke University

A fundamental problem in vision is that information in visual stimuli cannot be mapped unambiguously back onto real-world sources, a quandary referred to as the "inverse optics problem". Thus with respect to the physical characteristics of light reaching the eye from any source, illumination, reflectance and transmittance are inevitably conflated in the retinal image. Since to be successful visually-guided behavior must deal appropriately with the physical sources of light stimuli, the uncertain relationship of retinal images and their real-world provenance presents a enormous challenge to understanding how visual systems operate. Much of our recent work on the statistical relationship between images and their natural sources indicates that visual percepts are in fact generated according to the empirical significance of light stimuli, rather than the characteristics of the stimuli as such. This evidence implies that visual processing is based on statistical information derived from past experience.

Culture and the Evolution of Cognition
Peter Richerson, Environmental Science and Policy, UC Davis

Culture and genes have coevolved in the human species. Culture is an inheritance system that evolves partly under genetic constraints. Lumsden and Wilson's leash metaphor is quite illuminating as far as it goes. However, cultural variation itself also responds to natural selection giving culture an ultimate causal role along side of genes. Imagine that the dog at the end of L&W's leash is large and willful. A good deal of evidence suggests that our large brain evolved mainly to acquire, store, manage, and use culture. Humans are skilled imitators and learn a cultural repertoire that rivals the genome in size. This repertoire plays a major role in structuring our cognition. Social cognition offers a good example of how gene-culture coevolution probably worked. Darwin proposed that humans had been subject to group selection at the tribal level. However, human populations are usually rather outbred and are not good candidates for group selection at this scale. Group selection on cultural variation is more plausible. Under cultural group selection, humans became docile and empathic. Most people readily learn and conform to the social institutions of their societies. Given this social cognition, we can readily organize cooperation even with unrelated strangers.

Do We Have an Innate Moral Sense?
Jesse J. Prinz, Philosophy, UNC

There is an emerging consensus that human being have an innate moral faculty. Arguments for this conclusion run parallel to those that have been used to support linguistic nativism. There are alleged moral universals, moral knowledge emerges without sufficient instruction, moral rules appear to be modular, morality can be selectively impaired, and evolutionary precursors of morality can be found in nonhuman animals. Despite all these arguments, I argue that the evidence for an innate moral faculty is inadequate. It is more likely that morality, like religion, is a product of cultural evolution emerging from other capacities. To make this case, I examine work in psychology, neuroscience, ethology, and cultural anthropology.

The Evolution of Language in Communities of Neural Nets - Niche Construction or Meme Selection?
Justin C. Fisher, Philosophy, University of Arizona

My presentation will have two related goals. First, I will present some of my own computer modeling research involving the cultural evolution of language. This modeling work undercuts widely held versions of Linguistic Nativism by demonstrating that many striking features of natural languages might arise naturally from the dynamics of a cultural transmission process even in the complete absence of innate linguistic knowledge. This work is also interesting because it may serve as a manageable case study for general questions regarding cultural evolution and niche construction. The second goal of my presentation is to sketch answers to some of these questions.

Although I will briefly mention related modeling work by several researchers, I will concentrate primarily on my own work (in progress) studying the cultural development of language-like systems of communication in communities of neural networks. These nets engage in practical tasks which prompt them to learn to extract relevant information from the 'utterances' of other nets, and to learn to produce informative utterances themselves. Periodically, older nets are killed off and replaced by 'infant' nets. Over time, the result is that the community settles upon a communication system that is quite quickly learnable, syntactically quite regular, and structurally similar to the languages that develop independently in other communities of nets. These results demonstrate that many striking features of human languages may emerge from the dynamics of cultural transmission, even in the complete absence of innate linguistic knowledge.

I propose a plausible way of understanding these results in terms of evolutionary competition between cultural replicators (or 'memes', as they are sometimes called). I also consider several potential ways of explaining these results as instances of niche construction, but tentatively conclude that viewing this case in terms of niche construction provides no advantages over viewing it in terms of meme selection.

Niche Construction and the Constructing of Niches: Missed Opportunities in the Study of Cultural Change
Emily Schultz, Sociology and Anthropology, St. Cloud State University

Niche construction is a concept that appears to have the potential to attract the attention of many cultural anthropologists who find post-sociobiology evolutionary thinking incapable of accommodating their understandings of human agency, human culture, and culture change. Unfortunately, its great promise seems to be undercut by the way it is currently implemented in evolutionary arguments that rely on replicator-based definitions of culture, such as that of Robert Aunger. By treating constructed niches as finished products whose reliable production can be taken for granted, such definitions wholly ignore skilled cultural practice, which plays a central role in concepts of culture held by many contemporary cultural anthropologists. This neglect of practice is particularly surprising in view of the fact that the term niche construction would seem to highlight the central role of skilled practical activity in the making of niches. A robust concept of niche construction and its role in human cultural evolution, I suggest, would not focus narrowly on the evolution of "mind," would be sensitive the embodied process of constructing niches over time, and would make room for the historical contingencies that can intervene in that process. Drawing on the work of anthropologist Tim Ingold, urban ethnographer Michael Peter Smith, and others, I present an alternative interpretation in which niche-constructing practical activity is connected to discussions of place-making, imagined communities and communities of practice in contemporary cultural anthropology.

Preferences and the problem of adaptive individual choice
Catherine Driscoll, Philosophy, NC State University

One phenomena that cultural evolutionists have to explain is the relative prevalence of highly adaptive human cultural behavior. In order for cultural evolutionary processes to reliably produce adaptive behavior, individuals have to be able to engage in adaptive individual choice- where an individual reliably acquires or learns a behavior that leads to an increase in that individual's fitness. However, fitness information (as such) about behavior is extremely impractical to acquire, since the fitness information is information about long term average reproductive success. Cultural evolutionists solve this problem by postulating that humans possess adaptive preferences which allow them to quickly and reliably choose behaviors that are maximally fit. However, adaptive preferences will then need to be both appropriate to an individual's environment (to make acquisition tractable) and fixed by natural selection (to be adaptive). But humans have lived in a wide variety of environments in their evolutionary history and selection is slow.

I argue that if the problem of adaptive individual choice is to be solved, we must use two kinds of adaptive preferences in social learning: a) innate, intrinsic fitness correlate (alpha) preferences, and b) socially transmitted (beta) preferences instrumental for alpha preferences. Alpha preferences represent extremely environment general fitness correlates, and are adaptations. Beta preferences make cultural acquisition more tractable because they are ecologically specific, and because they are derived from alpha preferences they are also (local) fitness correlates. Their social transmission eases the computational burden on the learner, since acquiring preferences appropriate for the environment is onerous. However, because they are instrumental, they can fail to correlate with fitness, explaining why human behavior is not always adaptive. The importance of beta preferences suggests that, contra Sterelny (2003) we do need instrumental preferences in the "wiring and connection facts" about the human mind.

What kind of environmental complexity selects for decision theory?
Marshall Abrams, Center for Philosophy of Biology, Duke University

The environmental complexity thesis (ECT) is the claim that natural selection for complex cognitive abilities is the result of living in complex environments. William Cooper has argued for a specific variant of ECT. He claims that there will be selection toward behavioral patterns that accord with (something like) decision theory when environments are so complex that few organisms in a population ever experience the same conditions. I argue that nearly every environment has this kind of structure. What is really needed to justify Cooper's thesis is that there be a certain kind of higher-level pattern to the complexity of an environment. It must be possible (and adaptive) for organisms' perceptual systems to group environmental states in such a way that there is significant variance in certain probabilities which are conditional on these groups. My discussion is relevant to more general versions of ECT as well as Cooper's.

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