Six of one, half dozen of the other: Suboptimal prioritizing for equal and unequal alternatives

Abstract

When presented with two difficult tasks and limited resources, it is better to focus on one task and complete it successfully than to divide your efforts and fail on both. Although this logic seems obvious, people demonstrate a surprising failure to apply it when faced with prioritizing dilemmas. In previous research, the choice about which task to prioritise was arbitrary, because both tasks were equally difficult and had the same reward for success. In a series of three experiments, we investigated whether the equivalence of two tasks contributes to suboptimal decisions about how to prioritize them. First, we made one task more difficult than the other. Second, we compared conditions in which both tasks had to be attempted to conditions in which participants had to select one. Third, participants chose whether to place an equal or unequal reward value onto the two tasks. Each of these experiments removed or manipulated the arbitrary nature of the decision between options, with the goal of facilitating optimal decisions about whether to focus effort on one goal or divide effort over two. None of these manipulations caused participants to uniformly adopt a more optimal strategy, with the exception of trials where participants voluntarily placed more reward on one task over the other. In these, choices were modified more effectively with task difficulty than in previous experiments. However, participants were more likely to choose to distribute rewards equally than unequally. The results demonstrate that equal rewards across two tasks are preferred over unequal, even though this reward equivalence leads to poorer task strategies and smaller gains.

The role of framing, agency and uncertainty in a focus-divide dilemma

“…To foreshadow the results, in Experiment 1 of the current report, we implemented the fire trucks task and found that unlike previous versions of the focus-divide dilemma (e.g., Clarke & Hunt, 2016 ; James et al, 2017 ; James et al, 2019 ; James et al, 2023 ; Morvan & Maloney, 2012 ), participants made choices that were closer to optimal. For the investigation of individual differences that was our original motivation, this is a limitation because participants are more uniform by virtue of being closer to optimal.…”

“…The sample size for this experiment was based on a power analysis as described by James and colleagues ( 2023 ). They used bootstrapping methods from previously collected focus-divide task datasets to simulate a small shift in position choices (0.05 of the normalised range) at different sample sizes.…”

“…Based on the data from Experiment 1, a power analysis similar to that of James et al ( 2022 ) was applied to justify the sample sizes used in Experiments 2 and 3. We used bootstrapping methods to simulate the hypothesis that agency over performance would shift decisions away from optimal.…”

“…First, a single cognitive bias such as risk aversion (Pratt, 1978 ) or loss aversion (Kahneman & Tversky, 1984 ) is unlikely because this would predict a consistent but suboptimal behavioural pattern; for example, if participants avoided the risk of selecting a single target, it would drive them to always divide. A consistent pattern is not observed: some participants consistently divide resources between both goals, some focus on one rather than the other, and most exhibit variation in strategy between these two extremes, but are not influenced systematically by changes in the difficulty of the task (see James et al, 2023 for a more detailed argument on this). Second, a possible lack of information, in line with Bounded Rationality (Simon, 1990 ), was assessed by James et al ( 2017 ).…”

“…This reflects a simple decision rule for optimal performance: focus when difficult, divide when easy. Surprisingly, previous research has demonstrated that deviation from this simple decision rule is typical, to the extent that participants exhibit a near-total failure to adjust their strategy with changes in task difficulty (Clarke & Hunt, 2016 ; Hunt et al, 2019 ; James et al, 2017 ; James et al, 2019 ; James et al, 2023 ; Morvan & Maloney, 2012 ). In this series of experiments, we present a new version of the focus-divide dilemma in which participants approach the optimal strategy, and test whether agency over elements of the task or uncertainty about choice outcomes underlie the difference from previous results.…”