Nudge to Health: Harnessing Decision Research to Promote Health Behavior

We review selected literature that examines how biases in decision making can be utilized to encourage individual health behavior, such as vaccination, and promote policy decisions, such as resource allocation. These studies use simple interventions to nudge people towards more optimal health decisions without restricting decision-makers’ freedom of choice. Examples include framing effects, defaults, implementation intentions, position effects, social norm, incentives, and emotions. We suggest that nudges are an effective way to promote healthy behavior. Research on health behavior indicates that, too often, individuals fail to do what is good for them by engaging in risky behavior and neglecting to take preventive measures. Meanwhile, research on decision making indicates that decision makers are often irrational, or biased, in the sense that their behavior deviates systematically from normative principles that would maximize their goal satisfaction, or utility (Baron, 2000; Baron, 2004). It may seem that humanity is fated to be both unhealthy and irrational. However, in the current paper we explore whether decision biases can be exploited to make us healthier. That is, we investigate whether psychological research about decision making can be harnessed to improve health behavior and health outcomes. We review selected recent research that addresses this question. Human beings are not perfect decision makers. Too often, they use mental short cuts or rules of thumb instead of making a comprehensive cost ⁄benefits analysis to arrive at a decision. Our tendency to conserve cognitive effort means that a majority of our daily decisions are made using System 1 thinking (fast, automatic, based on intuition, gut feelings, rules and heuristics), from which route to drive to work, what we put in our morning coffee, to what to order for lunch ⁄dinner. In contrast, some complicated decisions usually elicit System 2 thinking (slow, systematic, deliberative, based on reason and calculation), such as which stock performs better, and what kind of mortgage loans offers the best financial outcome (Kahneman, 2003). The field of judgment and decision making has traditionally examined biases and errors, which are common by-product of our reliance on System 1 thinking. A wellknown example of such biases and errors is the framing effect: two normatively equivalent descriptions of the same decision often lead to systematically different choices. In Tversky and Kahneman’s (1981) classic demonstration, participants were presented with a description of the outbreak of a new Asian disease that was expected to kill 600 people. Two strategies for combating the disease were described. For participants in the gain frame condition, the strategies were framed in terms of lives saved (save 200 for sure versus save 600 with a 1 ⁄3 probability and none with a 2 ⁄3 probability). For participants in the loss frame condition, the strategies were framed in terms of lives lost (400 die for Social and Personality Psychology Compass 7/3 (2013): 187–198, 10.1111/spc3.12019 a 2013 Blackwell Publishing Ltd sure versus none die with a 1 ⁄3 probability and 600 die with a 2 ⁄3 probability). Participants tended to choose the riskless option in the gain frame but the risky option in the loss frame. Of course, the two frames described exactly the same options, so the fact that participants’ responses were influenced by the framing condition represents an irrational bias, because it violates the rule of consistency as prescribed by normative decision theories. Prospect Theory (Kahneman & Tversky, 1979) explains this bias as a result of our different gut reactions to risk for gains and for losses. In the domain of health, decision biases may lead to suboptimal health behavior and outcome (see Chapman, 2004, for a review). One approach to improving health behavior would be to devise methods to help decision makers avoid biases and inconsistencies as demonstrated above. According to this approach, helping people make more rational decisions means that they will make better choices, or at least choices more in line with their own preferences (based on what they value). However, despite our best intentions, biases and errors are hard to eliminate, because after all, when making one of the thousands of daily decisions, we do not have unlimited resources (time, energy, mental capacity) to investigate every option we face and to compute the exact cost and benefit of all the options (Gigerenzer & Goldstein, 1996; Gigerenzer & Selten, 2001). An alternative approach, therefore, is to exploit decision biases and harness them in the name of encouraging healthy behavior (Loewenstein, Brennan, & Volpp, 2007). The 2009 publication of Nudge (Thaler & Sunstein, 2008) highlighted this approach whereby the decision architecture is designed so choice of the healthy option or prosocial behavior is facilitated. With this approach, the decision architect tries to nudge the decision maker toward a particular option. A highly cited example of such nudges is the default effect, or the tendency for decision makers to stick with the default (the option that takes effect if one does not make an explicit choice) regardless of which option is designated as the default. For example, in some European countries, everyone is presumed to be an organ donor unless they explicitly opt out. In comparison, in other European countries, everyone is presumed not to be an organ donor unless they explicitly opt in. Individuals in both systems have the choice to be an organ donor or not, but the default status is different. As a consequence, organ donation rates are much higher in countries where being an organ donor is a default (Johnson & Goldstein, 2003). In this paper we review a selection of the many studies that use nudge-like interventions to affect health decisions, that is, small, simple changes in the decision environment that nudge people towards more optimal health behavior without restricting their freedom of choice. Many such nudges derive from well-know decision biases, such as the default effects framing effects, and position effects. Other nudges take advantage of social psychological principles known to alter behavior without extensive interventions, such as social norms and implementation intentions. Two classes of health decisions are included in this review: One concerns personal decisions made by individual decision makers, such as whether to get a flu shot, eat vegetables, or use sunscreen. The second type concerns policy decisions that will affect groups of people, such as how to allocate limited resources or whether to mandate a health behavior.