Variance-sensitive choice in lemurs: constancy trumps quantity

Numerous studies have demonstrated that animals’ tolerance for risk when foraging can be affected by changes in metabolic state. Specifically, animals on a negative energy budget increase their preferences for risk, while animals on a positive energy budget are typically risk-averse. The malleability of these preferences may be evolutionarily advantageous, and important for maximizing chances of survival during brief periods of energetic stress. However, animals adapted to living in unpredictable conditions are unlikely to benefit from risk-seeking strategies, and instead are expected to reduce energetic demands while maintaining risk-aversion. We measured risk preferences in lemurs, a group of primates restricted to the island of Madagascar. Lemurs have evolved diverse anatomical and behavioral traits for survival in a harsh and unpredictable ecology, and these traits have been explained as forms of anatomical and behavioral risk reduction. We therefore predicted that lemurs would also be risk-averse in a behavioral task that offered subjects a choice between a small certain reward, and an uncertain but potentially large reward. In Experiment 1, the average rewards associated with the constant and variable options were equal and lemurs exhibited high levels of risk-aversion, replicating a phenomenon that has been demonstrated in dozens of taxa. In Experiment 2, we gradually increased the average value of the variable option relative to the constant option. Lemurs’ preferences tracked these changes and subjects became more risk-seeking as the risk premium increased. However, many subjects maintained high levels of risk-aversion even when the average payout of the variable option yielded double that of the constant option. These results are consistent with the notion that lemur cognition has evolved to minimize risk in an unpredictable island environment.     

Expansion of Genetic Services Utilizing a General Genetic Counseling Clinic

We established a general genetic counseling clinic (GCC) to help reduce long wait times for new patient appointments and to enhance services for a subset of patients. Genetic counselors, who are licensed in Tennessee, were the primary providers and MD geneticists served as medical advisors. This article describes the clinic referral sources, reasons for referral and patient dispositions following their GCC visit(s). We obtained patients by triaging referrals made to our medical genetics division. Over 24 months, our GCC provided timely visits for 321 patients, allowing the MD geneticists to focus on patients needing a clinical exam and/or complex medical management. Following their GCC visit(s), over 80 % of patients did not need additional appointments with an MD geneticist. The GCC allowed the genetic counselor to spend more time with patients than is possible in our traditional medical genetics clinic. Patient satisfaction surveys (n?=?30) were very positive overall concerning the care provided. Added benefits for the genetic counselors were increased professional responsibility, autonomy and visibility as health care providers. We conclude that genetic counselors are accepted as health care providers by patients and referring providers for a subset of clinical genetics cases. A GCC can expand genetic services, complement more traditional genetic clinic models and utilize the strengths of the genetic counselor health care provider.     

Do nonhuman animals reason about prestige-based status?

Status is a complex, but crucially important, aspect of life across species. In recent decades, researchers have made significant contributions to our understanding of both the pathways by which status can be attained, as well as our underlying capacities for reasoning about these pathways. In 2001, Henrich & Gil-White proposed a prestige-based pathway to status where low status actors willingly defer to competent or knowledgeable high status actors, as a means of facilitating social learning and cultural transmission. Although this type of status hierarchy, and the capacity to reason about it, was hypothesized to be unique to humans, here I argue that there are several reasons why we might observe prestige-based status, and the capacity for reasoning about this pathway to status, in some nonhuman species as well. These reasons focus on the prevalence, importance, and sophistication of social learning in certain taxa, as well as the marked variation in hierarchy characteristics and structure across species. I point out places where our current methodologies encounter difficulties distinguishing whether a hierarchy in the wild is based on dominance or prestige, where our experimental methods leave us unable to assess whether an individual is reasoning about a high status actor as being prestigious or formidable, and provide suggestions for addressing these limitations. Adopting a comparative approach will clarify whether prestige-based status truly is unique to humans, and—if not—precisely what selective pressures facilitate the emergence of prestige-based status and the capacity for reasoning about it.