45 research outputs found

    The correct way to test the hypothesis that racial categorization is a byproduct of an evolved alliance-tracking capacity

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    Why evolutionary psychology should abandon modularity

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    A debate surrounding modularity—the notion that the mind may be exclusively composed of distinct systems or modules—has held philosophers and psychologists captive for nearly 40 years. Concern about this thesis—which has come to be known as the massive modularity debate—serves as the primary grounds for skepticism of evolutionary psychology’s claims about the mind. In this article we argue that the entirety of this debate, and the very notion of massive modularity itself, is ill-posed and confused. In particular, it is based on a confusion about the level of analysis (or reduction) at which one is approaching the mind. Here we provide a framework for clarifying at what level of analysis one is approaching the mind and explain how a systemic failure to distinguish between different levels of analysis has led to profound misunderstandings of not only evolutionary psychology but also of the entire cognitivist enterprise of approaching the mind at the level of the mechanism. We furthermore suggest that confusions between different levels of analysis are endemic throughout the psychological sciences—extending well beyond issues of modularity and evolutionary psychology. Therefore, researchers in all areas should take preventive measures to avoid this confusion in the future

    Behavioural outcomes of housing for domestic dog puppies (Canis lupus familiaris)

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    Domestic dogs experience a sensitive period for learning during early life and conditions during this time can have important consequences in the adult. We investigated the effects of kennel environment during early life, comparing the temperaments of puppies reared in indoor kennels, located in the breeder’s house, with those reared in outdoor kennels, located outside the breeder’s house and with limited human contact. The study was conducted on 264 puppies from 44 litters belonging to 21 breeds. Of these, 160 puppies were reared in indoor kennels (70 female and 90 male puppies, 27 litters) and 104 in outdoor kennels (52 female and 52 male, 17 litters). We conducted PAT (Puppy Aptitude Testing) tests to measure puppy temperament at an age of seven or eight weeks. Using a gamma GLMM fitted using Bayesian inference, we showed a statistically important effect of kennelling on posterior mean PAT scores. Puppies kennelled outdoors scored higher on PAT testing, irrespective of sex or age, and after accommodating for dependency in the data due to litter identity. Puppies raised outdoors showed an elevated tendency for submissive behaviour, a greater risk of aggression through fear, and a lowered capacity for coping with novel conditions. These findings have direct implications for dog breeders and illustrates that enrichment of the environment of dam and puppies can mitigate the risk of behavioural problems in adult dogs

    MMTF: The Maryland-Magellan Tunable Filter

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    This paper describes the Maryland-Magellan Tunable Filter (MMTF) on the Magellan-Baade 6.5-meter telescope. MMTF is based on a 150-mm clear aperture Fabry-Perot (FP) etalon that operates in low orders and provides transmission bandpass and central wavelength adjustable from ~5 to ~15 A and from ~5000 to over ~9200 A, respectively. It is installed in the Inamori Magellan Areal Camera and Spectrograph (IMACS) and delivers an image quality of ~0.5" over a field of view of 27' in diameter (monochromatic over ~10'). This versatile and easy-to-operate instrument has been used over the past three years for a wide variety of projects. This paper first reviews the basic principles of FP tunable filters, then provides a detailed description of the hardware and software associated with MMTF and the techniques developed to observe with this instrument and reduce the data. The main lessons learned in the course of the commissioning and implementation of MMTF are highlighted next, before concluding with a brief outlook on the future of MMTF and of similar facilities which are soon coming on line.Comment: 38 pages, 12 figures, 3 tables, now accepted for publication to the Astronomical Journa

    A prototype of a large tunable Fabry–Pérot interferometer for solar spectroscopy

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    Large Fabry-Pérot Interferometers (FPIs) are used in a variety of astronomical instrumentation, including spectro-polarimeters for 4 m class solar telescopes. In this work we comprehensively characterize the cavity of a prototype 150 mm FPI, sporting a novel, fully symmetric design. Of particular interest, we define a new method to properly assess the gravity effects on the interferometer's cavity when the system is used in either the vertical or horizontal configuration, both typical of solar observations. We show that the symmetric design very effectively limits the combined effects of pre-load and gravity forces to only a few nm over a 120 mm diameter illuminated surface, with gravity contributing ~2 nm peak-to-valley (~0.3 nm rms) in either configuration. We confirm a variation of the tilt between the plates of the interferometer during the spectral scan, which can be mitigated with appropriate corrections to the spacing commands. Finally, we show that the dynamical response of the new system fully satisfies typical operational scenarios. We conclude that large, fully symmetric FPIs can be safely used within solar instrumentation in both, horizontal and vertical position, with the latter better suited to limiting the overall volume occupied by such an instrument

    The evolution of primate short-term memory

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    Short-term memory is implicated in a range of cognitive abilities and is critical for understanding primate cognitive evolution. To investigate the effects of phylogeny, ecology and sociality on short-term memory, we tested the largest and most diverse primate sample to date (421 non-human primates across 41 species) in an experimental delayed-response task. Our results confirm previous findings that longer delays decrease memory performance across species and taxa. Our analyses demonstrate a considerable contribution of phylogeny over ecological and social factors on the distribution of short-term memory performance in primates; closely related species had more similar short-term memory abilities. Overall, individuals in the branch of Hominoidea performed better compared to Cercopithecoidea, who in turn performed above Platyrrhini and Strepsirrhini. Interdependencies between phylogeny and socioecology of a given species presented an obstacle to disentangling the effects of each of these factors on the evolution of shortterm memory capacity. However, this study offers an important step forward in understanding the interspecies and individual variation in short-term memory ability by providing the first phylogenetic reconstruction of this trait’s evolutionary history. The dataset constitutes a unique resource for studying the evolution of primate cognition and the role of short-term memory in other cognitive abilities
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