Archive

Archive for the ‘Proceedings of the National Academy of Sciences’ Category

Sound credit scores and financial decisions despite cognitive aging

January 23, 2015 Comments off

Sound credit scores and financial decisions despite cognitive aging (PDF)
Source: Proceedings of the National Academy of Sciences

At a time when the world’s 65-and-older population will double by 2035, policy changes have transferred many complex financial and healthcare decisions to individuals. Age-related declines in cognitive ability raise the specter that older adults facing major financial decisions may find them increasingly challenging. We explore whether knowledge and expertise accumulated from past decisions can offset age-related cognitive declines. Using a unique dataset that combines measures of cognitive ability, knowledge, and credit scores—a measure of creditworthiness that reflects sustained ability for sound financial decision-making—we find that cognitive decline does not spell doom. Instead, domain-specific knowledge and expertise provide an alternative route to sound financial decisions. These results suggest guidelines for designing effective interventions and decision aids across the life span.

Private traits and attributes are predictable from digital records of human behavior

January 19, 2015 Comments off

Private traits and attributes are predictable from digital records of human behavior (PDF)
Source: Proceedings of the National Academy of Sciences

We show that easily accessible digital records of behavior, Facebook Likes, can be used to automatically and accurately predict a range of highly sensitive personal attributes including: sexual orientation, ethnicity, religious and political views, personality traits, intelligence, happiness, use of addictive substances, parental separation, age, and gender. The analysis presented is based on a dataset of over 58,000 volunteers who provided their Facebook Likes, detailed demographic profiles, and the results of several psychometric tests. The proposed model uses dimensionality reduction for preprocessing the Likes data, which are then entered into logistic/linear regression to predict individual psychodemographic profiles from Likes. The model correctly discriminates between homosexual and heterosexual men in 88% of cases, African Americans and Caucasian Americans in 95% of cases, and between Democrat and Republican in 85% of cases. For the personality trait “Openness,” prediction accuracy is close to the test–retest accuracy of a standard personality test. We give examples of associations between attributes and Likes and discuss implications for online personalization and privacy.

Recent shifts in the occurrence, cause, and magnitude of animal mass mortality events

January 17, 2015 Comments off

Recent shifts in the occurrence, cause, and magnitude of animal mass mortality events (PDF)
Source: Proceedings of the National Academy of Sciences

Mass mortality events (MMEs) are rapidly occurring catastrophic demographic events that punctuate background mortality levels. Individual MMEs are staggering in their observed magnitude: re- moving more than 90% of a population, resulting in the death of more than a billion individuals, or producing 700 million tons of dead biomass in a single event. Despite extensive documentation of individual MMEs, we have no understanding of the major features characterizing the occurrence and magnitude of MMEs, their causes, or trends through time. Thus, no framework exists for contextualizing MMEs in the wake of ongoing global and regional perturbations to natural systems. Here we present an analysis of 727 published MMEs from across the globe, affecting 2,407 animal populations. We show that the magnitude of MMEs has been intensifying for birds, fishes, and marine invertebrat es; invariant for mammals; and decreasing for reptiles and amphibians. These shifts in magnitude proved robust when we accounted for an increase in the occurrence of MMEs since 1940. However, it remains unclear whether the increase in the occurrence of MMEs represents a true pattern or simply a perceived increase. Regardless, the increase in MMEs appears to be associated with a rise in disease emergence, biotoxicity, and events produced by multiple interacting stressors, yet temporal trends in MME causes varied among taxa and may be associated with increased de- tectability. In addition, MMEs with the largest magnitudes were those that resulted from multiple stressors, starvation, and disease. These results advance our understanding of rare demographic processes and their relationship to global and regional perturba- tions to natural systems.

See: Mass Die-Offs of Birds and Fish on the Rise (AllGov.com)

A generation at risk: Young investigators and the future of the biomedical workforce

January 12, 2015 Comments off

A generation at risk: Young investigators and the future of the biomedical workforce (PDF)
Source: Proceedings of the National Academy of Sciences

A number of distressing trends, including a decline in the share of key research grants going to younger scientists, as well as a steady rise in the age at which investigators receive their first funding, are now a decades-long feature of the US biomedical research workforce. Working committees have proposed recommendations, policy makers have implemented reforms, and yet the trajectory of our funding regime away from young scientists has only worsened. An investigation of some of the major factors and their geneses at play in explaining the increasing average age to first RO1 is presented. Recommendations related to funding, peer review, career paths, and the university–government partnership are provided.

The ecology of religious beliefs

January 5, 2015 Comments off

The ecology of religious beliefs
Source: Proceedings of the National Academy of Sciences

Although ecological forces are known to shape the expression of sociality across a broad range of biological taxa, their role in shaping human behavior is currently disputed. Both comparative and experimental evidence indicate that beliefs in moralizing high gods promote cooperation among humans, a behavioral attribute known to correlate with environmental harshness in nonhuman animals. Here we combine fine-grained bioclimatic data with the latest statistical tools from ecology and the social sciences to evaluate the potential effects of environmental forces, language history, and culture on the global distribution of belief in moralizing high gods (n = 583 societies). After simultaneously accounting for potential nonindependence among societies because of shared ancestry and cultural diffusion, we find that these beliefs are more prevalent among societies that inhabit poorer environments and are more prone to ecological duress. In addition, we find that these beliefs are more likely in politically complex societies that recognize rights to movable property. Overall, our multimodel inference approach predicts the global distribution of beliefs in moralizing high gods with an accuracy of 91%, and estimates the relative importance of different potential mechanisms by which this spatial pattern may have arisen. The emerging picture is neither one of pure cultural transmission nor of simple ecological determinism, but rather a complex mixture of social, cultural, and environmental influences. Our methods and findings provide a blueprint for how the increasing wealth of ecological, linguistic, and historical data can be leveraged to understand the forces that have shaped the behavior of our own species.

Evening use of light-emitting eReaders negatively affects sleep, circadian timing, and next-morning alertness

December 24, 2014 Comments off

Evening use of light-emitting eReaders negatively affects sleep, circadian timing, and next-morning alertness
Source: Proceedings of the National Academy of Sciences

In the past 50 y, there has been a decline in average sleep duration and quality, with adverse consequences on general health. A representative survey of 1,508 American adults recently revealed that 90% of Americans used some type of electronics at least a few nights per week within 1 h before bedtime. Mounting evidence from countries around the world shows the negative impact of such technology use on sleep. This negative impact on sleep may be due to the short-wavelength–enriched light emitted by these electronic devices, given that artificial-light exposure has been shown experimentally to produce alerting effects, suppress melatonin, and phase-shift the biological clock. A few reports have shown that these devices suppress melatonin levels, but little is known about the effects on circadian phase or the following sleep episode, exposing a substantial gap in our knowledge of how this increasingly popular technology affects sleep. Here we compare the biological effects of reading an electronic book on a light-emitting device (LE-eBook) with reading a printed book in the hours before bedtime. Participants reading an LE-eBook took longer to fall asleep and had reduced evening sleepiness, reduced melatonin secretion, later timing of their circadian clock, and reduced next-morning alertness than when reading a printed book. These results demonstrate that evening exposure to an LE-eBook phase-delays the circadian clock, acutely suppresses melatonin, and has important implications for understanding the impact of such technologies on sleep, performance, health, and safety.

Links that speak: The global language network and its association with global fame

December 23, 2014 Comments off

Links that speak: The global language network and its association with global fame
Source: Proceedings of the National Academy of Sciences

Languages vary enormously in global importance because of historical, demographic, political, and technological forces. However, beyond simple measures of population and economic power, there has been no rigorous quantitative way to define the global influence of languages. Here we use the structure of the networks connecting multilingual speakers and translated texts, as expressed in book translations, multiple language editions of Wikipedia, and Twitter, to provide a concept of language importance that goes beyond simple economic or demographic measures. We find that the structure of these three global language networks (GLNs) is centered on English as a global hub and around a handful of intermediate hub languages, which include Spanish, German, French, Russian, Portuguese, and Chinese. We validate the measure of a language’s centrality in the three GLNs by showing that it exhibits a strong correlation with two independent measures of the number of famous people born in the countries associated with that language. These results suggest that the position of a language in the GLN contributes to the visibility of its speakers and the global popularity of the cultural content they produce.

Follow

Get every new post delivered to your Inbox.

Join 1,001 other followers