Did social cognition evolve by cultural group selection?

Abstract Cognitive gadgets puts forward an ambitious claim: language, mindreading, and imitation evolved by cultural group selection. Defending this claim requires more than Heyes' spirited and effective critique of nativist claims. The latest human “cognitive gadgets,” such as literacy, did not spread through cultural group selection. Why should social cognition be different? The book leaves this question pending. It also makes strong assumptions regarding cultural evolution: it is moved by selection rather than transformation; it relies on high-fidelity imitation; it requires specific cognitive adaptations to cultural learning. Each of these assumptions raises crucial yet unaddressed difficulties

Accurate photonic temporal mode analysis with reduced resources

The knowledge and thus characterization of the temporal modes of quantum light fields is important in many areas of quantum physics ranging from experimental setup diagnosis to fundamental-physics investigations. Recent results showed how the auto-correlation function computed from continuous-wave homodyne measurements can be a powerful way to access the temporal mode structure. Here, we push forward this method by providing a deeper understanding and by showing how to extract the amplitude and phase of the temporal mode function with reduced experimental resources. Moreover, a quantitative analysis allows us to identify a regime of parameters where the method provides a trustworthy reconstruction, which we illustrate experimentally

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, 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”.Introduction Selection and nestedness in cultural collections The shortlist effect and its consequences in movie collections Discussion Materials and method

Decoherence-protected memory for a single-photon qubit

The long-lived, efficient storage and retrieval of a qubit encoded on a photon is an important ingredient for future quantum networks. Although systems with intrinsically long coherence times have been demonstrated, the combination with an efficient light-matter interface remains an outstanding challenge. In fact, the coherence times of memories for photonic qubits are currently limited to a few milliseconds. Here we report on a qubit memory based on a single atom coupled to a high-finesse optical resonator. By mapping and remapping the qubit between a basis used for light-matter interfacing and a basis which is less susceptible to decoherence, a coherence time exceeding 100 ms has been measured with a time-independant storage-and-retrieval efficiency of 22%. This demonstrates the first photonic qubit memory with a coherence time that exceeds the lower bound needed for teleporting qubits in a global quantum internet.Comment: 3 pages, 4 figure