Nursing home staff networks and COVID-19.

Nursing homes and other long-term care facilities account for a disproportionate share of COVID-19 cases and fatalities worldwide. Outbreaks in US nursing homes have persisted despite nationwide visitor restrictions beginning in mid-March. An early report issued by the Centers for Disease Control and Prevention identified staff members working in multiple nursing homes as a likely source of spread from the Life Care Center in Kirkland, WA, to other skilled nursing facilities. The full extent of staff connections between nursing homes-and the role these connections serve in spreading a highly contagious respiratory infection-is currently unknown given the lack of centralized data on cross-facility employment. We perform a large-scale analysis of nursing home connections via shared staff and contractors using device-level geolocation data from 50 million smartphones, and find that 5.1% of smartphone users who visited a nursing home for at least 1 h also visited another facility during our 11-wk study period-even after visitor restrictions were imposed. We construct network measures of connectedness and estimate that nursing homes, on average, share connections with 7.1 other facilities. Traditional federal regulatory metrics of nursing home quality are unimportant in predicting outbreaks, consistent with recent research. Controlling for demographic and other factors, a home's staff network connections and its centrality within the greater network strongly predict COVID-19 cases.

Political storms: Emergent partisan skepticism of hurricane risks.

Mistrust of scientific evidence and government-issued guidelines is increasingly correlated with political affiliation. Survey evidence has documented skepticism in a diverse set of issues including climate change, vaccine hesitancy, and, most recently, COVID-19 risks. Less well understood is whether these beliefs alter high-stakes behavior. Combining GPS data for 2.7 million smartphone users in Florida and Texas with 2016 U.S. presidential election precinct-level results, we examine how conservative-media dismissals of hurricane advisories in 2017 influenced evacuation decisions. Likely Trump-voting Florida residents were 10 to 11 percentage points less likely to evacuate Hurricane Irma than Clinton voters (34% versus 45%), a gap not present in prior hurricanes. Results are robust to fine-grain geographic controls, which compare likely Clinton and Trump voters living within 150 m of each other. The rapid surge in media-led suspicion of hurricane forecasts-and the resulting divide in self-protective measures-illustrates a large behavioral consequence of science denialism.

The effect of partisanship and political advertising on close family ties.

Research on growing American political polarization and antipathy primarily studies public institutions and political processes, ignoring private effects, including strained family ties. Using anonymized smartphone-location data and precinct-level voting, we show that Thanksgiving dinners attended by residents from opposing-party precincts were 30 to 50 minutes shorter than same-party dinners. This decline from a mean of 257 minutes survives extensive spatial and demographic controls. Reductions in the duration of Thanksgiving dinner in 2016 tripled for travelers from media markets with heavy political advertising-an effect not observed in 2015-implying a relationship to election-related behavior. Effects appear asymmetric: Although fewer Democratic-precinct residents traveled in 2016 than in 2015, Republican-precinct residents shortened their Thanksgiving dinners by more minutes in response to political differences. Nationwide, 34 million hours of cross-partisan Thanksgiving dinner discourse were lost in 2016 owing to partisan effects.

The Effect of Language on Economic Behavior: Evidence from Savings Rates, Health Behaviors, and Retirement Assets.

Languages differ widely in the ways they encode time. I test the hypothesis that the languages that grammatically associate the future and the present, foster future-oriented behavior. This prediction arises naturally when well-documented effects of language structure are merged with models of intertemporal choice. Empirically, I find that speakers of such languages: save more, retire with more wealth, smoke less, practice safer sex, and are less obese. This holds both across countries and within countries when comparing demographically similar native households. The evidence does not support the most obvious forms of common causation. I discuss implications for theories of intertemporal choice.

How choice affects and reflects preferences: revisiting the free-choice paradigm.

After making a choice between 2 objects, people reevaluate their chosen item more positively and their rejected item more negatively (i.e., they spread the alternatives). Since Brehm's (1956) initial free-choice experiment, psychologists have interpreted the spreading of alternatives as evidence for choice-induced attitude change. It is widely assumed to occur because choosing creates cognitive dissonance, which is then reduced through rationalization. In this article, we express concern with this interpretation, noting that the free-choice paradigm (FCP) will produce spreading, even if people's attitudes remain unchanged. Specifically, if people's ratings/rankings are an imperfect measure of their preferences and their choices are at least partially guided by their preferences, then the FCP will measure spreading, even if people's preferences remain perfectly stable. We show this, first by proving a mathematical theorem that identifies a set of conditions under which the FCP will measure spreading, even absent attitude change. We then experimentally demonstrate that these conditions appear to hold and that the FCP measures a spread of alternatives, even when this spreading cannot have been caused by choice. We discuss how the problem we identify applies to the basic FCP paradigm as well as to all variants that examine moderators and mediators of spreading. The results suggest a reassessment of the free-choice paradigm and, perhaps, the conclusions that have been drawn from it.

Endowment effect in capuchin monkeys.

In humans, the capacity for economically rational choice is constrained by a variety of preference biases: humans evaluate gambles relative to arbitrary reference points; weigh losses heavier than equally sized gains; and demand a higher price for owned goods than for equally preferred goods that are not yet owned. To date, however, fewer studies have examined the origins of these biases. Here, we review previous work demonstrating that human economic biases such as loss aversion and reference dependence are shared with an ancestrally related New World primate, the capuchin monkey (Cebus apella). We then examine whether capuchins display an endowment effect in a token-trading task. We identified pairs of treats (fruit discs versus cereal chunks) that were equally preferred by each monkey. When given a chance to trade away their owned fruit discs to obtain the equally valued cereal chunks (or vice versa), however, monkeys required a far greater compensation than the equally preferred treat. We show that these effects are not due to transaction costs or timing issues. These data suggest that biased preferences rely on cognitive systems that are more evolutionarily ancient than previously thought-and that common evolutionary ancestry shared by humans and capuchins may account for the occurrence of the endowment effect in both species.

Modeling reciprocation and cooperation in primates: evidence for a punishing strategy.

Experiments in which animals strategically interact with one another or search over some controlled domain are becoming common. While these experiments often promise to illuminate sophisticated animal behavior, the analyses brought to bear on these data are often quite coarse. For example, many papers simply tally the number of observations consistent with a behavioral theory. This analysis is simple, but ignores a potentially rich source of information by failing to take into account patterns and systematic variation among observations inconsistent with the theory. Using a new data set generated by cotton-top tamarin monkeys playing a repeated food-exchange game, we apply a maximum-likelihood estimation technique (more commonly used to study human economic behavior) which utilizes much more of the information in these data, and which uncovers unexpectedly sophisticated cooperative behavior from our subjects. Tamarin cooperation remains stable as long as both actors consistently cooperate, but requires at least two consecutive unexpected acts of cooperation to restart cooperation after it has collapsed, a strategy that resembles two-tits for a tat. We conclude by enumerating the benefits of a maximum-likelihood approach in experimental settings such as ours, and suggest other areas in which these techniques may be fruitful.

Give unto others: genetically unrelated cotton-top tamarin monkeys preferentially give food to those who altruistically give food back.

Altruistic food giving among genetically unrelated individuals is rare in nature. The few examples that exist suggest that when animals give food to unrelated others, they may do so on the basis of mutualistic or reciprocally altruistic relationships. We present the results of four experiments designed to tease apart the factors mediating food giving among genetically unrelated cotton-top tamarins (Saguinus oedipus), a cooperatively breeding New World primate. In experiment 1 we show that individuals give significantly more food to a trained conspecific who unilaterally gives food than to a conspecific who unilaterally never gives food. The apparent contingency of the tamarins' food-giving behaviour motivated the design of experiments 2-4. Results from all three experiments show that altruistic food giving is mediated by prior acts of altruistic food giving by a conspecific. Specifically, tamarins do not give food to unrelated others when the food received in the past represents the by-product of another's selfish actions (experiments 2 and 3) or when a human experimenter gives them food (experiment 4) as did the unilateral altruist in experiment 1. By contrast, if one tamarin gives another food without obtaining any immediate benefit, then the recipient is more likely to give food in return. Overall, results show that tamarins altruistically give food to genetically unrelated conspecifics, discriminate between altruistic and selfish actions, and give more food to those who give food back. Tamarins therefore have the psychological capacity for reciprocally mediated altruism.