Ellen Peters

University of Oregon | UO

Whether to undergo genome sequencing in a clinical or research context is generally a voluntary choice. Individuals are often motivated to learn genomic information even when clinical utility-the possibility that the test could inform medical recommendations or health outcomes-is low or absent. Motivations to seek one's genomic information can be c...

Numeracy—the ability to understand and use numeric information—is linked to good decision-making. Several problems exist with current numeracy measures, however. Depending on the participant sample, some existing measures are too easy or too hard; also, established measures often contain items well-known to participants. The current article aimed t...

Innumeracy (lack of math skills) among non-scientists often leads climate scientists and others to avoid communicating numbers due to concerns that the public won’t understand them and may disengage. However, people report preferring to receive numbers; providing them also improves some decisions. Here, we demonstrate that providing numbers in clim...

Cell phone use while driving (CUWD) is an underreported contributor to crashes in the U.S.A. Although research indicates that the public is at least somewhat aware of its risks, law enforcement officers’ beliefs have been understudied. Officers’ attitudes are important for the following reasons: they influence citation rates; enforcement of the law...

Driving evaluations aim to ensure adequate skills; however, feedback beyond pass/fail is needed for improvement. Therefore, the goal of this study was to inform driving feedback report design to ensure ease of use and understandability while motivating improvements. Participants ages 18–25 years (n = 521) were recruited from CloudResearch Prime Pan...

Social and behavioral science research proliferated during the COVID-19 pandemic, reflecting the substantial increase in influence of behavioral science in public health and public policy more broadly. This review presents a comprehensive assessment of 742 scientific articles on human behavior during COVID-19. Two independent teams evaluated 19 sub...

Background Rates of contralateral prophylactic mastectomy (CPM)—removal of the healthy breast following breast cancer diagnosis—have increased, particularly among women for whom CPM provides no survival benefit. Affective (i.e., emotional) decision making is often blamed for this increase. We studied whether greater negative breast cancer affect co...

Four studies demonstrate that the public’s understanding of government budgetary expenditures is hampered by difficulty in representing large numerical magnitudes. Despite orders of magnitude difference between millions and billions, study participants struggle with the budgetary magnitudes of government programs. When numerical values are rescaled...

Encouraging vaccine uptake is important to reducing the impact of infectious disease. However, negative attitudes and vaccine hesitancy, due in part to worry about side effects, are obstacles to achieving high vaccination rates. Provided vaccine information sheets typically include a list of side effects without numeric information about their like...

Climate change poses a multifaceted, complex, and existential threat to human health and well-being, but efforts to communicate these threats to the public lag behind what we know how to do in communication research. Effective communication about climate change’s health risks can improve a wide variety of individual and population health-related ou...

Background Objective numeracy appears to support better medical decisions and health outcomes. The more numerate generally understand and use numbers more and make better medical decisions, including more informed medical choices. Numeric self-efficacy—an aspect of subjective numeracy that is also known as numeric confidence—also relates to decisio...

Objectives To identify what patient-related characteristics have been reported to be associated with the occurrence of shared decision-making (SDM) about treatment. Design Scoping review. Eligibility criteria Peer-reviewed articles in English or Dutch reporting on associations between patient-related characteristics and the occurrence of SDM for...

Decision support techniques and online algorithms aim to help individuals predict costs and facilitate their choice of health insurance coverage. Self-reported health status (SHS), whereby patients rate their own health, could improve cost-prediction estimates without requiring individuals to share personal health information or know about undiagno...

Park and Brannon (2013, https://doi.org/10.1177/0956797613482944) found that practicing non-symbolic approximate arithmetic increased performance on an objective numeracy task, specifically symbolic arithmetic. Manipulating objective numeracy would be useful for many researchers, particularly those who wish to investigate causal effects of objectiv...

Objective numeracy, the ability to understand and use mathematical concepts, has been related to superior decisions and life outcomes. Unknown is whether it relates to greater satisfaction in life. We investigated numeracy’s relations with income satisfaction and overall life satisfaction in a diverse sample of 5,525 American adults. First, more nu...

Numeracy, the ability to understand and use basic probability and numerical concepts, is associated with diverse positive outcomes across the lifespan. Prior cross-sectional research on numeracy has generally found a negative association with age, but positive correlations with male gender, education attainment, and measures of fluid and crystalliz...

People higher (vs. lower) in objective numeracy—the ability to use probabilistic and mathematical concepts—use numeric information more when making decisions. Specifically, they are more sensitive to numeric levels than the less numerate and use more numeric versus nonnumeric information. Greater attention to numbers may explain this effect, but li...

Objective A large body of research has established that cellphone use while driving (CUWD) is common and dangerous. However, little research has been conducted about how people react psychologically to various distraction-reduction strategies and, ultimately, support or do not support them. Understanding support for reduction is important for predi...

In two large-scale longitudinal datasets (combined N = 5761), we investigated ability-related political polarization in responses to the COVID-19 pandemic. We observed more polarization with greater ability in emotional responses, risk perceptions, and product-purchase intentions across five waves of data collection with a diverse, convenience samp...

The University of Oregon’s “Emotions and Polarization in Decisions & Media in COVID-19” (UO-EPIDeMIC) study tracked perceptions of the COVID-19 pandemic from February 17th of 2020 through December 17th of 2020 in a single cohort of 1,284 American Mechanical Turk (MTurk) workers. Affect, attitudes, risk perceptions, intentions for protective behavio...

Background: Shared decision making requires evidence to be conveyed to the patient in a way they can easily understand and compare. Patient decision aids facilitate this process. This article reviews the current evidence for how to present numerical probabilities within patient decision aids. Methods: Following the 2013 review method, we assembl...

Background: Decision aid developers have to convey complex task-specific numeric information in a way that minimizes bias and promotes understanding of the options available within a particular decision. Whereas our companion paper summarizes fundamental issues, this article focuses on more complex, task-specific aspects of presenting numeric info...

Communities often unite during a crisis, though some cope by ascribing blame or stigmas to those who might be linked to distressing life events. In a preregistered two-wave survey, we evaluated the dehumanization of Asians and Asian Americans during the COVID-19 pandemic. Our first wave (March 26–April 2, 2020; N = 917) revealed dehumanization was...

Although inequality in the US has increased since the 1960s, several studies show that Americans underestimate it. Reasons include overreliance on one’s local perspective and ideologically-motivated cognition. We propose a novel mechanism to account for the misperceptions of income inequality. We hypothesize that compared to those who feel less aut...

Peters, E. (2020). Innumeracy in the Wild: Misunderstanding and Misusing Numbers . (New York, NY: Oxford University Press) 315 pp. ISBN 978-0190861094 This piece briefly introduces and excerpts Innumeracy in the Wild: Misunderstanding and Misusing Numbers , written by Ellen Peters and published by Oxford University Press. Through a state-of-art rev...

Aim: Research regarding decisions patients make about total knee arthroplasty, apart from having the procedure or not, are limited. Understanding patient decision making and related information needs is essential for shared decision making. Methods: Focus groups with an online community-based sample identified decisions about total knee arthroplast...

Background: Risk information in patient decision aids (PDAs) is often difficult for older patients to process. Providing audiovisual and narrative information may enhance the understanding and use of health-related information. We studied the effects on patients' information processing and use of audiovisual and narrative information of an early-s...

Objective: Appetitive risk behaviors (ARB), including tobacco use, alcohol consumption, consumption of calorie dense/nutrient-poor foods, and sexual risk behavior contribute substantially to morbidity and mortality. Affective states that arise from a wide array of unrelated circumstances (i.e., incidental affect) may carry over to influence ARB. A...

Aging is associated with declines in deliberative processing and associated decision-making quality. However, people over 65 years make many of our nation's most important decisions (think about the Supreme Court, governments, and corporations around the world), perhaps indicating that deliberative decline does not fully explain adult age differenc...

Acetaminophen, an analgesic and antipyretic available over-the-counter and used in over 600 medicines, is one of the most consumed drugs in the USA. Recent research has suggested that acetaminophen's effects extend to the blunting of negative as well as positive affect. Because affect is a determinant of risk perception and risk taking, we tested t...

Context: Little is known about the pathways mediating the relationship between education and health. It is widely assumed that formal schooling leads to awareness of health risks (e.g., STIs) and, in turn, to adoption of preventive behavior (e.g., condom use); however, evidence supporting this mechanism has been limited. Methods: Survey data wer...

This chapter, “Reliance on Heuristics and Concrete, Easy-to-Evaluate Attributes,” focuses on how the less objectively numerate rely on simpler, one-attribute decision making more than the highly numerate. In particular, the less objectively numerate are more likely to neglect provided statistics and decide based on the compelling power of stories....

This chapter, “Reflections on Numeracy and the Power of Reasoning Numerically,” looks back at what you have learned in this book. Innumeracy presents major challenges to people due to the ubiquity of numbers in daily decisions and the less objectively numerate’s inability to understand and use them appropriately. However, the less numerate can beco...

This chapter, “Evidence-Based Information Presentation Matters,” introduces the problem: poorly presented numbers, widespread innumeracy, and barriers introduced by the communicators themselves. These issues combine to produce negative consequences for health and financial well-being and for shared decisions about public resources. Because risk and...

This chapter, “Subjective Numeracy and Knowing What You Know,” reviews what is known about the role of subjective numeracy in decision making, independent of objective numeracy. In particular, it examines how numeric self-efficacy (confidence in one’s math ability) and math anxiety propel how much people understand and persist with numeric informat...

This chapter, “Innumeracy, Incomprehension, and Inconsistency,” is the first of three chapters focused on how the less objectively numerate make worse decisions when numbers are involved. The chapter makes two main points. First, the less objectively numerate understand numeric data less well, even after controlling for nonnumeric intelligence, edu...

This chapter “Thinking Harder with Numbers,” is the first of four chapters focusing on how more objectively numerate people think harder and, as a result, judge and decide better when numeric information is involved. First, they attend to and search for numeric information more than the less numerate do. Second, they think more with numbers by (1)...

This chapter, “Issues and Opportunities in Objective Numeracy Research,” discusses three cross-cutting questions in objective numeracy research. The first two issues concern the correlational nature of most objective numeracy research. Alternative explanations exist for the effects of numeracy on decisions and life outcomes. In particular, this cha...

This chapter, “Provide Evaluative Meaning and Direct Attention,” links earlier chapters about the habits of the highly numerate to evidence-based communication solutions that especially help the less objectively numerate. In particular, Chapter 17 provides techniques to assist decision makers when they are unable to evaluate the good or bad meaning...

This chapter, “Numeric Sensitivity and Consistent Use of Numbers,” provides further evidence of the highly numerate being more sensitive to and consistent with numbers in their judgments and decisions. The highly numerate simply have a numeric hammer that the less numerate do not possess. Some of this chapter’s evidence suggests that communicators...

This chapter, “Numeracy’s Secret Connection with Life Outcomes,” reviews available evidence for numeracy’s relations with outcomes in health, employment, and personal finances. Less numerate people tend to be less healthy than the highly numerate, with a 40% greater likelihood, for example, of having at least one chronic disease. Numeracy skills al...

This chapter, “Genetics and Formal Education,” reviews evidence for the genetic underpinnings of numeric competencies, the role of formal education in developing better numeric skills, and barriers to learning in school. Studies indicate some genetic influence on approximate number system (ANS) acuity (also called intuitive number sense), objective...

This chapter, “Training Numeracy,” focuses on improving numeric competencies to provide backdoor assistance to adults who want to make better decisions. The chapter reviews research on the roles of formal schooling in childhood and numeracy training in adulthood. It particularly highlights current evidence on adult trainings for objective numeracy...

This chapter, “Discriminating Numbers Allows for Better Decisions,” focuses on the role of our intuitive sense of numbers in decision making. Humans have evolved beyond these intuitions about quantities to know modern numeric abstractions. However, the evolutionarily old approximate number system (ANS) nonetheless remains pivotal to human decisions...

This chapter, “The Types and Extent of Innumeracy,” briefly describes three kinds of numeric competency. First, people can score high or low on tests of their understanding and use of mathematical concepts (called objective numeracy ). Objective innumeracy occurs across levels of education and is not the same as intelligence; very smart people can...

This chapter, “Numerically Imperfect Reasoning Among the Highly Numerate,” highlights the highly numerate as imperfect number crunchers. They are surprisingly prone to some of Chapter 3’s heuristics and biases. Their use of conditional probabilities (e.g., Bayes’ Theorem) is suboptimal at best, as is their ability for nonlinear numeric thinking, su...

This chapter, “The Highly Numerate Understand the Feel of Numbers,” discusses the critical importance to decision making of good and bad feelings derived from numeric information. Decisions are hard to make sometimes because we don’t have a feel for what an important number means. The highly numerate, however, appear to compare numbers more, derive...

Innumeracy in the Wild explains how numeric ability supports the quality of the decisions we make and, ultimately, the life outcomes we experience. It dissects three ways that people can be good or bad with numbers and how each of these numeric competencies matter to decision making. Furthermore, it delves into how we can use this knowledge to impr...

This chapter, “Feelings and Frames,” reviews research indicating that the less objectively numerate get carried away more by emotion, and they are more affected by how information is framed. In particular, they rely on the affect heuristic and use their feelings as a substitute for important numeric information. They are also more susceptible to at...

This chapter, “The Approximate Number System (ANS) and Discriminating Magnitudes,” discusses our intuitive, rather than deliberative, understanding of numbers. Humans are born with an innate sense of number and an ability to perform simple arithmetic operations with sets of objects without counting. We share this intuitive sense of numeric magnitud...

This chapter, “Provide Numbers but Reduce Cognitive Effort,” challenges the notion that numbers mislead people and should be avoided. This chapter recommends instead that communicators provide numeric information but reduce how much effort is required from consumers and patients to use it. In particular, the chapter discusses five ways that providi...

Objective: Greater numeracy is associated with higher likelihood to quit smoking. We examined whether numeracy supports learning of numeric health-risk information and, in turn, greater risk perceptions and quit intentions. Method: Adult smokers (N = 696) viewed text warnings with numeric risk information four times each in one of three warning-...

The COVID-19 pandemic represents a massive global health crisis. Because the crisis requires large-scale behaviour change and places significant psychological burdens on individuals, insights from the social and behavioural sciences can be used to help align human behaviour with the recommendations of epidemiologists and public health experts. Here...

The COVID-19 pandemic represents a massive, global health crisis. Because the crisis requires large-scale behavior change and poses significant psychological burdens on individuals, insights from the social and behavioural sciences are critical for optimizing pandemic response. Here we review relevant research from a diversity of research areas rel...

Background. Numeracy skills are important for medical decision making as lower numeracy is associated with misinterpreting statistical health risks. Math anxiety, characterized by negative emotions about numerical tasks, and lower subjective numeracy (i.e., self-assessments of numerical competence) are also associated with poor risk comprehension....

Risk perception is an important construct in many health behavior theories. Smoking risk perceptions are thoughts and feelings about the harms associated with cigarette smoking. Wide variation in the terminology, definition, and assessment of this construct makes it difficult to draw conclusions about the associations of risk perceptions with smoki...

Accumulating wealth is one of the main concerns for consumers. Higher education is widely associated with higher wealth, but the underlying reasons for this association remain unclear. Using data from a field study conducted with 218 adults in agrarian communities in Peru's Andean highlands, we explored the extent to which education, non‐numeric fl...

People often laugh about being “no good at math.” Unrecognized, however, is that about one-third of American adults are likely too innumerate to operate effectively in financial and health environments. Two numeric competencies conceivably matter—objective numeracy (ability to “run the numbers” correctly; like literacy but with numbers) and numeric...

Background The USA must publicly share information about harmful and potentially harmful constituents (chemicals) in tobacco products. We sought to understand whether webpages with chemical information are “understandable and not misleading to a lay person.” Methods Participants were a national probability sample of US adults and adolescents ( n =...

Context: Being diagnosed with cancer often forces patients and families to make difficult medical decisions. How patients think they and others will feel in the future, termed affective predictions, may influence these decisions. These affective predictions are often biased, which may contribute to suboptimal care outcomes by influencing decisions...

Objectives: We evaluated the association of health literacy and attention to the pictorial imagery of 9 health warning labels (HWLs) in a tobacco advertisement among rural US smokers. We hypothesized that lower health literacy would be associated with greater visual attention to pictorial portions of HWLs and evaluated the association between heal...

Objectives: E-cigarettes are now the most commonly-used tobacco product among adolescents; yet, little work has examined how the appealing food and flavor cues used in their marketing might attract adolescents' attention, thereby increasing willingness to try these products. In the present study, we tested whether advertisements for fruit/sweet/sa...

Background: Patient portals have emerged as an important tool through which patients can access online health information and engage in their health care. However, we know little about how patients perceive portals and whether patient perceptions might influence portal adoption. Objective: Apply the diffusion of innovation (DOI) theory to assess p...

Introduction: Health numeracy helps individuals understand risk information, but limited data exist concerning numeracy's role in reactions to varying types of health warning labels (HWLs) for cigarettes. Methods: A nationally representative online panel of adult current smokers received two exposures (1 week apart) to nine HWLs with either text...

Understanding the public’s perceptions of risk is of great importance to governments, businesses, and scientists worldwide because the public influences what policies are enacted. As a result, how people perceive (and misperceive) the risks of various hazards and activities has been of interest to academic and other researchers for many years. Rese...

Objective To evaluate how demographics, health literacy, numeracy, and patient activation are related to transition readiness in adolescent and young adult (AYA) patients, and to describe how parent/guardian (PG) performance on these metrics predicts AYA transition readiness. Methods In this single center, cross‐sectional study, consecutive Englis...

OBJECTIVE: To investigate Ob-Gyns’ counseling practices and perspectives pertaining to obesity in the context of a diagnosis of endometrial hyperplasia and carcinoma. STUDY DESIGN: We conducted a national survey of practicing Ob-Gyns, who were recruited through the Collaborative Ambulatory Research Network. RESULTS: The response rate to our survey...

Background Pictorial cigarette warning labels are thought to increase risk knowledge, but experimental research has not examined longer-term effects on memory for health risks named in text. Purpose To investigate memory-consolidation predictions that high- versus low-emotion warnings would support better long-term memory for named cigarette healt...

DS_10.1177_2381468318781093 – Supplemental material for A Comparison Between Subjective and Objective Methods of Predicting Health Care Expenses to Support Consumers’ Health Insurance Plan Choice

Psychologists have convincingly demonstrated that preferences are not always stable and, instead, are often “constructed” based on information available in the judgment or decision context. In 4 studies with experts (accountants and actuaries in Studies 1 and 2, respectively) and a diverse lay population (Studies 3 and 4), the evidence was consiste...

Objective. Numerous electronic tools help consumers select health insurance plans based on their estimated health care utilization. However, the best way to personalize these tools is unknown. The purpose of this study was to compare two common methods of personalizing health insurance plan displays: 1) quantitative healthcare utilization predictio...

Background Systemic lupus erythematous (SLE) is a heterogeneous disease with high morbidity and mortality with complex long-term treatments. These dynamic treatments can be daunting especially to the 25%–60% of SLE patients who have cognitive and neuropsychiatric deficits. Patients lacking understanding of their own baseline health status and treat...

Background Patients have a poor understanding of outcomes related to total knee replacement (TKR) surgery, with most underestimating the potential benefits and overestimating the risk of complications. In this study, we sought to compare the impacts of descriptive information alone or in combination with an icon array (IA), experience condition (im...

Objectives: In the U.S., print advertisements for smokeless tobacco (SLT) feature a large black-and-white text warning covering 20% of the advertisement space. Cigarette and e-cigarette advertisements feature a small warning covering approximately 4% of advertisement space. We explored how warning size affects adolescent boys' spontaneous recollec...

Objective: The US government requires the public display of information about toxic chemicals in cigarettes and smoke by brand in a way that is understandable and not misleading. We sought to identify risk communication formats that meet these goals. Methods: We conducted 3 online experiments with US adult convenience samples (total N = 1866). P...

Background: Despite recently expanded access to health insurance, consumers still face barriers to using their coverage to obtain needed health care. Objective: To examine the characteristics of those who delay or avoid health care due to costs. Methods: Participants were recruited via Amazon MTurk and completed a survey assessing demographic chara...

Background: The World Health Organization's Framework Convention on Tobacco Control recommends prominent pictorial health warnings on tobacco products. To advance research methods, theory and understanding of how tobacco product warning labels (TPWLs) work, the US National Cancer Institute convened a grantee meeting. Our article describes the key...

The Family Smoking Prevention and Tobacco Control Act requires the US government to inform the public about the quantities of toxic chemicals in cigarette smoke. A website can accomplish this task efficiently, but the site’s user interface must be usable to benefit the general public. We conducted online experiments with national convenience sample...

Can we educate decision-makers to make better decisions? In the present paper, I argue that we can in at least two broad ways: (1) teaching concrete knowledge about a specific decision or decision type; and (2) teaching more abstract decision-making competencies that are thought to lead to better decisions. Teaching knowledge can be done using deci...

Self-regulation is a broad construct representing the general ability to recruit cognitive, motivational and emotional resources to achieve long-term goals. This construct has been implicated in a host of health-risk behaviors, and is a promising target for fostering beneficial behavior change. Despite its clear importance, the behavioral, psycholo...

Objective: To determine if 1) patients have distinct affective reaction patterns to medication information, and 2) whether there is an association between affective reaction patterns and willingness to take medication. Methods: We measured affect in real time as subjects listened to a description of benefits and side effects for a hypothetical n...

We sought to identify icons to effectively communicate health harms of chemicals in cigarette smoke. Participants were a convenience sample of 701 U.S. adults. A within-subjects online experiment explored the effects of icon semiotic type: symbolic (arbitrary, most abstract), indexical, and iconic (representative, most concrete). Outcomes were perc...

Greater numeracy has been correlated with better health and financial outcomes in past studies, but causal effects in adults are unknown. In a 9-week longitudinal study, undergraduate students, all taking a psychology statistics course, were randomly assigned to a control condition or a values-affirmation manipulation intended to improve numeracy....

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