Chimpanzees and bonobos distinguish between risk and ambiguity

Although recent research has investigated animal decision-making under risk, little is known about how animals choose under conditions of ambiguity when they lack information about the available alternatives. Many models of choice behaviour assume that ambiguity does not impact decision-makers, but studies of humans suggest that people tend to be more averse to choosing ambiguous options than risky options with known probabilities. To illuminate the evolutionary roots of human economic behaviour, we examined whether our closest living relatives, chimpanzees (Pan troglodytes) and bonobos (Pan paniscus), share this bias against ambiguity. Apes chose between a certain option that reliably provided an intermediately preferred food type, and a variable option that could vary in the probability that it provided a highly preferred food type. To examine the impact of ambiguity on ape decision-making, we interspersed trials in which chimpanzees and bonobos had no knowledge about the probabilities. Both species avoided the ambiguous option compared with their choices for a risky option, indicating that ambiguity aversion is shared by humans, bonobos and chimpanzees.     

State Dependent Valuation: The Effect of Deprivation on Risk Preferences

The internal state of an organism affects its choices. Previous studies in various non-human animals have demonstrated a complex, and in some cases non-monotonic, interaction between internal state and risk preferences. Our aim was to examine the systematic effects of deprivation on human decision-making across various reward types. Using both a non-parametric approach and a classical economic analysis, we asked whether the risk attitudes of human subjects towards money, food and water rewards would change as a function of their internal metabolic state. Our findings replicate some previous work suggesting that, on average, humans become more risk tolerant in their monetary decisions, as they get hungry. However, our specific approach allowed us to make two novel observations about the complex interaction between internal state and risk preferences. First, we found that the change in risk attitude induced by food deprivation is a general phenomenon, affecting attitudes towards both monetary and consumable rewards. But much more importantly, our data indicate that rather than each subject becoming more risk tolerant as previously hypothesized based on averaging across subjects, we found that as a population of human subjects becomes food deprived the heterogeneity of their risk attitudes collapses towards a fixed point. Thus subjects who show high-risk aversion while satiated shift towards moderate risk aversion when deprived but subjects who are risk tolerant become more risk averse. These findings demonstrate a more complicated interaction between internal state and risk preferences and raise some interesting implications for both day-to-day decisions and financial market structures.     

Evolving public perceptions and stability in vaccine uptake

Recent vaccine scares and sudden spikes in vaccine demand remind us that the effectiveness of mass vaccination programs is governed by the public perception of vaccination. Previous work has shown that the tendency of individuals to optimize self-interest can lead to vaccination levels that are suboptimal for a community. We use game theory to relate population-level demand for vaccines to decision-making by individuals with varied beliefs about the costs of infection and vaccination. In contrast to previous work proposing that universal vaccination is impossible in a game theoretic context, we show that optimal individual behavior can vary between universal vaccination and no vaccination, depending on the relative costs and benefits to individuals. By coupling game models and epidemic models, we demonstrate that the pursuit of self-interest often leads to stable dynamics but can lead to oscillations in vaccine uptake over time. The instability is exacerbated in populations that are more homogeneous with respect to their perceptions of vaccine and infection risks. This research illustrates the importance of applying temporal models to an inherently temporal situation, namely, the time evolution of vaccine coverage in an informed population with a voluntary vaccination policy.     

A Food Scare a Day: Why Aren't We Better at Managing Dietary Risk?

Does the existence of food scares mean that we are bad at risk management? Not necessarily. New information brings new risks to the forefront or puts known risks into a new perspective. But in some cases food scares do indicate poor risk management. There are two key problems that explain why we are not better at managing dietary risks. The first is an imbalance of effort among the three components of risk analysis: we have Hummer risk assessment, Yugo risk management, and tricycle risk communication. The second problem is inadequate risk management. The cases of risks from mad cow disease and dioxins illustrate how the quality of risk management is affected by what we do not know well enough, what we know too well, and what we have not tried to find out. Better risk management requires a two-tier approach: (1) generate broad and shallow information on risks, health outcomes, incentives, options, benefits, and costs (Toyota Prius Hybrid risk management to be used everyday) and (2) generate narrow and in-depth information on high priority risks (Hummer risk assessment to be used sparingly).     

Organizing effects of testosterone and economic behavior: not just risk taking

Recent literature emphasizes the role that testosterone, as well as markers indicating early exposure to T and its organizing effect on the brain (such as the ratio of second to fourth finger, [Formula: see text]), have on performance in financial markets. These results may suggest that the main effect of T, either circulating or in fetal exposure, on economic behavior occurs through the increased willingness to take risks. However, these findings indicate that traders with a low digit ratio are not only more profitable, but more able to survive in the long run, thus the effect might consist of more than just lower risk aversion. In addition, recent literature suggests a positive correlation between abstract reasoning ability and higher willingness to take risks. To test the two hypotheses of testosterone on performance in financial activities (effect on risk attitude versus a complex effect involving risk attitude and reasoning ability), we gather data on the three variables in a sample of 188 ethnically homogeneous college students (Caucasians). We measure a [Formula: see text] digit ratio, abstract reasoning ability with the Raven Progressive Matrices task, and risk attitude with choice among lotteries. Low digit ratio in men is associated with higher risk taking and higher scores in abstract reasoning ability when a combined measure of risk aversion over different tasks is used. This explains both the higher performance and higher survival rate observed in traders, as well as the observed correlation between abstract reasoning ability and risk taking. We also analyze how much of the total effect of digit ratio on risk attitude is direct, and how much is mediated. Mediation analysis shows that a substantial part of the effect of T on attitude to risk is mediated by abstract reasoning ability.     

A stakeholder perspective into wildlife policy in India

We investigated perceptions of wildlife policy and issues through questionnaires (n = 148) administered to policy makers, conservation scientists, individuals representing non-government organizations (NGOs), and field officials, who implemented government policies and enforced laws. We found significant differences among attitudes of stakeholders identifying major threats to wildlife, the use of science, the role of poaching in conservation, and the composition of species illegally traded. Policy makers and field officials differed in their views with NGOs and scientists on community response to wildlife policies and the varying threat perceptions to different species due to poaching and illegal trade. We noted ambiguity among stakeholders about sustainable use principles in India. Policies must be more effective in conservation and the process of making policy must be broad-based and participatory if wildlife conservation is to advance on the subcontinent. © 2011 The Wildlife Society.     

Bistability of Evolutionary Stable Vaccination Strategies in the Reinfection SIRI Model

We use the reinfection SIRI epidemiological model to analyze the impact of education programs and vaccine scares on individuals decisions to vaccinate or not. The presence of the reinfection provokes the novelty of the existence of three Nash equilibria for the same level of the morbidity relative risk instead of a single Nash equilibrium as occurs in the SIR model studied by Bauch and Earn (PNAS 101:13391–13394, 2004). The existence of three Nash equilibria, with two of them being evolutionary stable, introduces two scenarios with relevant and opposite features for the same level of the morbidity relative risk: the low-vaccination scenario corresponding to the evolutionary stable vaccination strategy, where individuals will vaccinate with a low probability; and the high-vaccination scenario corresponding to the evolutionary stable vaccination strategy, where individuals will vaccinate with a high probability. We introduce the evolutionary vaccination dynamics for the SIRI model and we prove that it is bistable. The bistability of the evolutionary dynamics indicates that the damage provoked by false scares on the vaccination perceived morbidity risks can be much higher and much more persistent than in the SIR model. Furthermore, the vaccination education programs to be efficient they need to implement a mechanism to suddenly increase the vaccination coverage level.     

The Public and Professionals Reason Similarly about the Management of Non-Native Invasive Species: A Quantitative Investigation of the Relationship between Beliefs and Attitudes

Despite continued critique of the idea of clear boundaries between scientific and lay knowledge, the ‘deficit-model’ of public understanding of ecological issues still seems prevalent in discourses of biodiversity management. Prominent invasion biologists, for example, still argue that citizens need to be educated so that they accept scientists’ views on the management of non-native invasive species. We conducted a questionnaire-based survey with members of the public and professionals in invasive species management (n = 732) in Canada and the UK to investigate commonalities and differences in their perceptions of species and, more importantly, how these perceptions were connected to attitudes towards species management. Both native and non-native mammal and tree species were included. Professionals tended to have more extreme views than the public, especially in relation to nativeness and abundance of a species. In both groups, species that were perceived to be more abundant, non-native, unattractive or harmful to nature and the economy were more likely to be regarded as in need of management. While perceptions of species and attitudes towards management thus often differed between public and professionals, these perceptions were linked to attitudes in very similar ways across the two groups. This suggests that ways of reasoning about invasive species employed by professionals and the public might be more compatible with each other than commonly thought. We recommend that managers and local people engage in open discussion about each other’s beliefs and attitudes prior to an invasive species control programme. This could ultimately reduce conflict over invasive species control.     

Risk aversion and religious behaviour: Analysis using a sample of Danish twins

Economics offers an analytical framework to consider human behaviour including religious behaviour. Within the realm of Expected Utility Theory, religious belief and activity could be interpreted as an insurance both for current life events and for afterlife rewards. Based on that framework, we would expect that risk averse individuals would demand a more generous protection plan which they may do by devoting more effort and resources into religious activities such as church attendance and prayer, which seems to be in accordance with previous empirical results. However, a general concern regards the problems of spurious correlations due to underlying omitted or unobservable characteristics shaping both religious activities and risk attitudes. This paper examines empirically the demand for religion by analysing the association between risk attitudes on the one hand, and church attandance and prayer frequency on the other controlling for unobservable variables using survey data of Danish same-sex twin pairs. We verify the correlation between risk preferences and religion found previously by carrying out cross-sectional analyses. We also show that the association between risk attitudes and religious behaviour is driven by the subgroup of individuals who believe in an afterlife. In addition, when re-analysing our results using panel data analyses which cancel out shared factors among twin pairs, we find that the correlation found between risk aversion and religious behaviour is no longer significant indicating that other factors might explain differences in religious behaviour. Caution is needed in the interpretation of our results as the insignificant association between risk aversion and religious behaviour in the panel data analyses potentially might be due to measurement error causing attenuation bias or lack of variation within twin pairs rather than the actual absence of an association.     

Science,Politics and Policy: How Michiganders think about the Risks Facing the Great Lakes

The Great Lakes region is an important ecological asset for the United States, yet studies show that several environmental risks threaten its viability. As a result, it is important to respond to these risks with effective policies. When and how policy is implemented often depends on public opinion and perceptions; yet, we understand little about how individuals from the Great Lakes region construct opinions about the threats facing the lakes. We seek to understand how individuals from the state of Michigan form opinions on three risks to the lakes: invasive Asian carp, climate change, and offshore drilling. To do this, we evaluate the utility of two dominant models of environmental opinion formation: trust and deference to scientific authority, and partisan bias and motivated reasoning. We find that when issues have been politicized, opinion is greatly influenced by political factors like partisanship but that trust and deference as well as underlying environmental attitudes play a more important role for issues that have not been politicized. We discuss the implications of these findings in terms of policy and communication in Michigan, arguing that if we want Michiganders to support policy consistent with science, they must view risk in ways that are consistent with scientific consensus. For that to happen, advocates and policy makers must focus on reducing the political rhetoric around these threats, developing communication that taps into underlying trust and deference to science, and using underlying attitudes about the role of government in environmental protection to promote environmental policy.     

Ecological Risk Aversion and Foraging Behaviors of Juvenile Squirrel Monkeys (Saimiri sciureus)

The ‘ecological risk aversion hypothesis’ [C.H. Janson and C.P. van Schaik, Juvenile Primates, Oxford Univ. Press, New York (1993), pp. 57–74] proposes that the pattern of slow growth characteristic of juvenile primates is a response to ecological risks (predation and starvation) experienced by juveniles. Juveniles are thought to avoid predation risk by positioning themselves near conspecifics, therefore experiencing high levels of feeding competition with older individuals, reduced access to resources and, consequently, high starvation risks during periods of food scarcity. The present study compared the foraging behaviors of juvenile and adult squirrel monkeys, a small neotropical primate characterized by a long juvenile period, to determine how predation and starvation risks affected juvenile behaviors. The study was conducted in Eastern Amazonia, in a seasonal environment. Due to their slow development, small body size and large group sizes, it was expected that juveniles in this species would behave in a manner consistent with the risk aversion hypothesis. However, age differences in foraging efficiency and foraging success were smaller than predicted. There was also no evidence that juveniles sacrificed access to food for predator protection. Adults did not have preferential access to fruit patches and direct competition was rare. Feeding competition for prey, the most common resource in the troop's diet, was negligible. Therefore, the slow growth and long juvenile period of squirrel monkeys do not correspond with evidence of predation or starvation risk, as predicted by the risk aversion hypothesis.     

Are Non-Native Plants Perceived to Be More Risky? Factors Influencing Horticulturists' Risk Perceptions of Ornamental Plant Species

Horticultural trade is recognized as an important vector in promoting the introduction and dispersal of harmful non-native plant species. Understanding horticulturists'' perceptions of biotic invasions is therefore important for effective species risk management. We conducted a large-scale survey among horticulturists in Switzerland (N = 625) to reveal horticulturists'' risk and benefit perceptions from ornamental plant species, their attitudes towards the regulation of non-native species, as well as the factors decisive for environmental risk perceptions and horticulturists'' willingness to engage in risk mitigation behavior. Our results suggest that perceived familiarity with a plant species had a mitigating effect on risk perceptions, while perceptions of risk increased if a species was perceived to be non-native. However, perceptions of the non-native origin of ornamental plant species were often not congruent with scientific classifications. Horticulturists displayed positive attitudes towards mandatory trade regulations, particularly towards those targeted against known invasive species. Participants also expressed their willingness to engage in risk mitigation behavior. Yet, positive effects of risk perceptions on the willingness to engage in risk mitigation behavior were counteracted by perceptions of benefits from selling non-native ornamental species. Our results indicate that the prevalent practice in risk communication to emphasize the non-native origin of invasive species can be ineffective, especially in the case of species of high importance to local industries and people. This is because familiarity with these plants can reduce risk perceptions and be in conflict with scientific concepts of non-nativeness. In these cases, it might be more effective to focus communication on well-documented environmental impacts of harmful species.     

Evolutionary game theory and social learning can determine how vaccine scares unfold

Immunization programs have often been impeded by vaccine scares, as evidenced by the measles-mumps-rubella (MMR) autism vaccine scare in Britain. A "free rider" effect may be partly responsible: vaccine-generated herd immunity can reduce disease incidence to such low levels that real or imagined vaccine risks appear large in comparison, causing individuals to cease vaccinating. This implies a feedback loop between disease prevalence and strategic individual vaccinating behavior. Here, we analyze a model based on evolutionary game theory that captures this feedback in the context of vaccine scares, and that also includes social learning. Vaccine risk perception evolves over time according to an exogenously imposed curve. We test the model against vaccine coverage data and disease incidence data from two vaccine scares in England & Wales: the whole cell pertussis vaccine scare and the MMR vaccine scare. The model fits vaccine coverage data from both vaccine scares relatively well. Moreover, the model can explain the vaccine coverage data more parsimoniously than most competing models without social learning and/or feedback (hence, adding social learning and feedback to a vaccine scare model improves model fit with little or no parsimony penalty). Under some circumstances, the model can predict future vaccine coverage and disease incidence--up to 10 years in advance in the case of pertussis--including specific qualitative features of the dynamics, such as future incidence peaks and undulations in vaccine coverage due to the population's response to changing disease incidence. Vaccine scares could become more common as eradication goals are approached for more vaccine-preventable diseases. Such models could help us predict how vaccine scares might unfold and assist mitigation efforts.     

Deactivation of dietary wariness through experience of novel food

When a forager encounters an unfamiliar type of food, it mustdecide whether to eat it and risk being poisoned or avoid eatingit and risk forfeiting a potentially valuable resource. Birdstypically respond to such situations with "dietary wariness";they show a transient aversion to approaching new food (neophobia),and many individuals also show a much longer lasting reluctanceto consume the new food (dietary conservatism), even once neophobiahas waned. Very little is known about how these processes, togethertermed "wariness," are controlled. We therefore present a seriesof experiments investigating how wariness of novel foods indomestic chicks, Gallus gallus domesticus, can be deactivatedand reactivated by different experiences of colored foods, varyingin their degree of novelty and palatability. We found that priorexperience of a single novel color of palatable chick crumbswas sufficient to deactivate both neophobia and dietary conservatismof any other novel color of crumbs tested. Relatively littleprior experience of a novel training food was needed to deactivateneophobia, after which the birds would peck at any other novelfood. In contrast, much more extensive experience of eatinga novel training food was needed before the birds would incorporateother novel foods into their diet. Chicks needed direct physicalcontact with the training food before they overcame their warinessto eat another novel food. However, observational learning wassufficient to encourage them to peck at the food (overcomingtheir neophobia). Reinstating wariness was much more easilyachieved than its deactivation. We discuss these surprisingresults in relation to the foraging behavior of wild and domesticbirds.     

Conscious Augmentation of Creative State Enhances “Real” Creativity in Open-Ended Analogical Reasoning

Humans have an impressive ability to augment their creative state (i.e., to consciously try and succeed at thinking more creatively). Though this “thinking cap” phenomenon is commonly experienced, the range of its potential has not been fully explored by creativity research, which has often focused instead on creativity as a trait. A key question concerns the extent to which conscious augmentation of state creativity can improve creative reasoning. Although artistic creativity is also of great interest, it is creative reasoning that frequently leads to innovative advances in science and industry. Here, we studied state creativity in analogical reasoning, a form of relational reasoning that spans the conceptual divide between intelligence and creativity and is a core mechanism for creative innovation. Participants performed a novel Analogy Finding Task paradigm in which they sought valid analogical connections in a matrix of word-pairs. An explicit creativity cue elicited formation of substantially more creative analogical connections (measured via latent semantic analysis). Critically, the increase in creative analogy formation was not due to a generally more liberal criterion for analogy formation (that is, it appeared to reflect “real” creativity rather than divergence at the expense of appropriateness). The use of an online sample provided evidence that state creativity augmentation can be successfully elicited by remote cuing in an online environment. Analysis of an intelligence measure provided preliminary indication that the influential “threshold hypothesis,” which has been proposed to characterize the relationship between intelligence and trait creativity, may be extensible to the new domain of state creativity.     

Linking risk attitudes,time preferences,and body mass index in Catalonia

Obesity is projected to increase in the coming years, despite the various socioeconomic policies implemented by governments and policy makers. As a result, some studies have suggested that obesity should be looked at from a psychological point of view, that is, individuals’ propensity to become addicted to the consumption of fat-rich foods. Although previous studies have supported this, the results have been inconclusive: methodologically and geographically. This study uses a robust approach to elicit the risk and time preferences of food consumers. It goes further to ascertain the correlations between these parameters and obesity. Despite the methodological and geographical differences, our results support a strong relationship between body mass Index and risk aversion, but not for loss aversion. In addition, time discounting significantly influences individuals’ propensity to increase body mass Index.     

Evaluating the Influence of the Presence of a Dog on Bias toward Individuals with Overweight and Obesity

Individuals with overweight and obesity are subject to enormous bias and discrimination across domains. This bias constitutes a considerable public health problem beyond the effects of excess weight on health. Unfortunately, the few interventions that have been implemented to reduce this bias have not been successful. Evidence that the presence of an animal makes individuals and settings appear more attractive, desirable, approachable, and relaxed, as well as happier and safer, suggests that dog ownership may be a simple way to reduce weight bias. Accordingly, we tested whether the presence of a dog can reduce weight bias in a sample of 314 online participants. Each participant was presented with a stimulus image representing one of three conditions (person with dog, person with plant, or person alone), and was then asked to rate the human model using three measures. Two sets of stimuli (featuring different models) were used to ensure that findings were not restricted to a particular model. Contrary to our predictions, we found no evidence that the presence of a dog affects endorsement of weight-related stereotypes, general evaluations, or desire for social distance. These findings contrast with a large body of literature showing that dogs enhance perceptions of a range of individuals and settings. The effect of dogs on perceptions may be restricted in the case of weight bias because of the pervasive, explicit, and severe nature of this bias. Dogs may have stronger effects on attitudes that are less openly endorsed. Promising avenues where dogs are very likely to influence attitudes include perceptions of individuals of different racial and ethnic backgrounds, gender identities, and even political parties.     

Measuring rice farmers’ risk perceptions and attitude: Evidence from Pakistan

Abstract

The agriculture sector is confronting numerous types of risk. Like other crops’ farmers, rice growers are also facing multifarious challenges, including production and environmental risk. On the one hand, they are suffering from water shortage. On the other hand, if a flood occurs, there is no proper water reservation management, especially in developing countries. Global warming is another erotic topic for agriculture sustainability. To address the growers’ perceptions and their attitudes toward such types of risks, a farm base survey was carried out, and rice farmers were investigated in Pakistan. Methods of equally likely certainty equivalent and risk matrix were applied to investigate the farmers’ risk perceptions and attitude. A probit model was also used to estimate the factors that influence farmers’ perceptions and attitudes toward risks. The outcomes of the study show that flood, input high prices, increasing temperature, and crop diseases are the perceiving risks among rice farmers. Different types of socio-economic factors are influencing farmers’ risk perceptions and their attitudes, such as age, education level, a distance of farms from rivers, and non-farm income. This study provides valuable information to the policymakers and concerning authorities to apprehend agricultural risks among rice farmers and farming sustainability, especially in developing countries.     

Attitudes toward genetic testing for cancer risk after genetic counseling and decision support: a qualitative comparison between hereditary cancer types

This study aimed to qualitatively assess individuals' attitudes toward genetic testing for cancer risk after genetic counseling and decision support. As part of a larger study, 78 women considering genetic testing for hereditary breast/ovarian cancer (HBOC) risk and 22 individuals considering genetic testing for hereditary nonpolyposis colorectal cancer (HNPCC) completed an open-ended table of their perceived pros and cons of genetic testing. The most frequently reported pros were "to help manage my risk of developing cancer," "to help my family," and "to know my cancer risk." With regards to risk management, the HBOC group perceived genetic testing as most helpful in informing their general risk management practices, while the HN-PCC group focused on the potential to clarify their need for bowel cancer screening, suggesting that patients' perceptions of the benefits of genetic testing may differ across cancer syndromes. Individuals in both groups expressed concern about the potential psychological impact of genetic testing. We also found that some affected individuals may not fully comprehend the meaning of their potential test results. Eliciting patients' perceived pros and cons during genetic counseling is likely to be a valuable tool for improving patient care. This data also provides an improved evidence base for the development of patient education tools.