Over-Imitation in the Kalahari Desert and the Origins of Human Cultural Cognition

Children grow up in environments saturated with tools and objects which they must learn to use. One of the most efficient ways in which children do this is by imitating. Recent work has shown that, in contrast to non-human primates, when young children learn by imitating they focus more on reproducing the specific actions used than the actual outcomes achieved. From about 18 months of age children will routinely copy arbitrary and unnecessary actions. This puzzling behaviour is called 'over-imitation'. By documenting similarities exhibited by children from a large, industrialised city and children from remote Bushman communities in southern Africa, we provide here the first indication that over-imitation is a universal human trait. We also show that over-imitation is unaffected by the age of the child, testing environment, or familiarity of the demonstrating adult. Furthermore we argue that, although seemingly maladaptive, over-imitation reflects an evolutionary adaptation fundamental to the development and transmission of human culture

William James and the Evolution of Consciousness

Despite having been relegated to the realm of superstition during the dominant years of behaviourism, the investigation and discussion of consciousness has again become scientifically defensible. However, attempts at describing animal consciousness continue to be criticised for lacking independent criteria that identify the presence or absence of the phenomenon. Over one hundred years ago William James recognised that mental traits are subject to the same evolutionary processes as are physical characteristics and must therefore be represented in differing levels of complexity throughout the animal kingdom. James's proposals with regard to animal consciousness are outlined and followed by a discussion of three classes of animal consciousness derived from empirical research. These classes are presented to defend both James's proposals and the position that a theory of animal consciousness can be scientifically supported. It is argued that by using particular behavioural expressions to index consciousness and by providing empirical tests by which to elicit these behavioural expressions a scientifically defensible theory of animal consciousness can be developed

Summer Residency of Pacific Halibut in Glacier Bay National Park

Glacier Bay National Park (Fig.1), as a Marine Protected Area (MPA), is phasing out commercial fishing of Pacific halibut (Hippoglossus stenolepis) within the park. The species continues to be commercially harvested outside of the bay

The imitative behaviour of children and chimpanzees: A window on the transmission of cultural traditions

Humans engage in a multitude of complex social activities that, depending on such things as shared history, proximity, language and identification, can be engaged in differently from one community to another. Humans are a cultural species: But we are not the only ones. An array of behaviours indicative of cultural variation has been identified in chimpanzees, our closest living relatives, that has yet to be found in any other nonhuman animal. However, the breadth and depth of these behaviours seem insignificant when compared to the profound cultural variation inherent in human social behaviour. The source of differences between humans and chimpanzees in the proliferation of cultural traditions may be attributed to differences in the way these species engage in imitation. Human children show a strong tendency to imitate the actions of others at the expense of producing the functional outcomes of those actions, a tendency that chimpanzees do not show. It is argued that this tendency is an outcome of young children’s motivation to be social and to interact with others, and it is this that has driven the proliferation of human culture

Continuously non-malleable codes with split-state refresh

Non-malleable codes for the split-state model allow to encode a message into two parts, such that arbitrary independent tampering on each part, and subsequent decoding of the corresponding modified codeword, yields either the same as the original message, or a completely unrelated value. Continuously non-malleable codes further allow to tolerate an unbounded (polynomial) number of tampering attempts, until a decoding error happens. The drawback is that, after an error happens, the system must self-destruct and stop working, otherwise generic attacks become possible. In this paper we propose a solution to this limitation, by leveraging a split-state refreshing procedure. Namely, whenever a decoding error happens, the two parts of an encoding can be locally refreshed (i.e., without any interaction), which allows to avoid the self-destruct mechanism. An additional feature of our security model is that it captures directly security against continual leakage attacks. We give an abstract framework for building such codes in the common reference string model, and provide a concrete instantiation based on the external Diffie-Hellman assumption. Finally, we explore applications in which our notion turns out to be essential. The first application is a signature scheme tolerating an arbitrary polynomial number of split-state tampering attempts, without requiring a self-destruct capability, and in a model where refreshing of the memory happens only after an invalid output is produced. This circumvents an impossibility result from a recent work by Fuijisaki and Xagawa (Asiacrypt 2016). The second application is a compiler for tamper-resilient RAM programs. In comparison to other tamper-resilient compilers, ours has several advantages, among which the fact that, for the first time, it does not rely on the self-destruct feature

Pea-barley intercrop N dynamics in farmers fields

Knowledge about crop performances in farmers’ fields provides a link between on-farm practice and re-search. Thereby scientists may improve their ability to understand and suggest solutions for the problems facing those who have the responsibility of making sound agricultural decisions. Nitrogen (N) availability is known to be highly heterogeneous in terrestrial plant communities (Stevenson and van Kessel, 1997), a heterogeneity that in natural systems is often associated with variation in the distri-bution of plant species. In intercropping systems the relative proportion of component crops is influenced by the distribution of growth factors such as N in both time and space (Jensen, 1996). In pea-barley intercrops, an increase in the N supply promotes the growth of barley thereby decreasing the N accumulation of pea and giving rise to changes in the relative proportions of the intercropped components (Jensen, 1996). The pres-sure of weeds may, however, significantly change the dynamics in intercrops (Hauggaard-Nielsen et al., 2001). Data from farmers’ fields may provide direct, spatially explicit information for evaluating the poten-tials of improving the utilisation of field variability by intercrops

The social glue of cumulative culture and ritual behavior

Abstract: Cumulative culture, where innovations are progressively incorporated into a population’s stock of skills and knowledge, generating ever more sophisticated repertoires, is a core aspect of human cognition that underpins the technological advances which characterize our species. Cumulative culture relies on our proclivity for high fidelity imitation, something that emerged phylogenetically early in our evolutionary history and emerges ontogenetically early in our development. Commensurate with this proclivity to copy others comes a tradeoff that functionally irrelevant behaviors will be easily maintained and transmitted. Rituals are an expression of this. In this paper, I set out the argument that the core cognitive architecture responsible for cumulative culture and technological progress has the same origin as that which propagates rituals: That is, our socially-motivated propensity for engaging in high-fidelity imitation

Tight Noise Thresholds for Quantum Computation with Perfect Stabilizer Operations

We study how much noise can be tolerated by a universal gate set before it loses its quantum-computational power. Specifically we look at circuits with perfect stabilizer operations in addition to imperfect non-stabilizer gates. We prove that for all unitary single-qubit gates there exists a tight depolarizing noise threshold that determines whether the gate enables universal quantum computation or if the gate can be simulated by a mixture of Clifford gates. This exact threshold is determined by the Clifford polytope spanned by the 24 single-qubit Clifford gates. The result is in contrast to the situation wherein non-stabilizer qubit states are used; the thresholds in that case are not currently known to be tight.Comment: 4 pages, 2 figure

Quantum Computation as Geometry

Quantum computers hold great promise, but it remains a challenge to find efficient quantum circuits that solve interesting computational problems. We show that finding optimal quantum circuits is essentially equivalent to finding the shortest path between two points in a certain curved geometry. By recasting the problem of finding quantum circuits as a geometric problem, we open up the possibility of using the mathematical techniques of Riemannian geometry to suggest new quantum algorithms, or to prove limitations on the power of quantum computers.Comment: 13 Pages, 1 Figur