The Sunk-Time Effect: An Exploration

Persevering in Fertility Treatments Despite Failures: Unrealistic Optimism and the Reality of a Pronatalist Culture

BACKGROUND

Fertility treatment discontinuation is difficult as it entails accepting childlessness. In most countries, financial limitations provide sufficient justification to terminate treatment. In Israel, unlimited funding enables women to undergo multiple treatment cycles, even when the odds of success are poor, thus providing a context for studying the psychological mechanisms involved when financial constraints are set aside. The study aimed to investigate the contribution of unrealistic optimism to Israeli women's willingness to continue fertility treatments even after repeated failures and to their psychological adjustment, comparing age groups.

METHODS

A longitudinal study of 100 women (ages 31-45) undergoing in vitro fertilization (IVF) treatment (1-22 previous cycles), who filled in questionnaires assessing their estimates of treatment success (theirs/for same-age patient), estimates received from the physician, intentions to continue treatment, and psychological adjustment. Follow-up was conducted 17(± 4) months later, by phone (n = 71) and/or medical records (n = 90).

RESULTS

Most women (57%) reported that they will continue as long as needed till they have a child, 13% did not know, and 25% mentioned a specific plan; 5 did not reply. Women's estimates of treatment success showed vast unrealistic optimism, which was unrelated to their age, history of unsuccessful treatment cycles, or intentions for treatment continuation, yet was related to better psychological adjustment. At follow-up, almost all women who did not conceive were found to have continued treatments.

CONCLUSIONS

Unrealistic optimism helps women maintain hope and well-being along the demanding journey to (biological) parenthood, where childlessness is highly stigmatized, and contributes to perseverance in treatment, regardless of objective factors.

The sunk-time effect: effect of time invested and reward magnitude using within-subject design

This study examines the sunk cost phenomenon in the temporal domain with human subjects. We used an adjusting procedure to quantitatively assess the effect of time on the value of an alternative. To explore whether a magnitude effect, similar to that documented in delay discounting studies, could be observed in a sunk cost scenario, we used a within-subject design with two different magnitudes. Two questionnaires were applied individually to 47 first-year psychology students. In each questionnaire, a hypothetical situation was presented in which participants were told that they had waited a certain amount of time to buy a guitar. Then, participants had to pay for the guitar and choose whether to keep it or sell it. Each questionnaire included five delay conditions (between one month and sixty months). The two questionnaires differed only in the nominal value of the guitar. In one of the questionnaires, a smaller magnitude was used (520 USD); in the other one, the value of the guitar was larger (3900 USD). The data suggest a sunk time effect and a linear increase in the subjective value of the alternatives proportional to the time invested. We found evidence of generality of the magnitude effect to the sunk cost scenario. Time investments caused a greater change in the value of outcomes of smaller magnitudes. We suggest that future research lines could evaluate the generality of these findings using different types of population, questionnaires, frames, delays, and commodities.

Behavioral Investments in the Short Term Fail to Produce a Sunk Cost Effect

A cognitive bias known as the sunk cost effect has been found across a number of contexts. This bias drives the continued investment of time, effort, or money into an endeavor on the basis of prior investments into it. In Studies 1 and 2, we attempted to observe whether this effect occurs for short-term behavioral investments. In both studies, a reverse, or no sunk cost effect was found. In Study 3, we attempted to find an effect using hypothetical scenarios that were analagous to the behavioral investments presented in Study 1. This also failed to reveal an effect. Finally, Study 4 was an attempt to replicate a previously used hypothetical investment scenario; with results this time revealing the effect. A number of explanations for this pattern of results, such as participation and salient physical exertion, are discussed, with the possibility that some short-term behavioral investments are not subject to the sunk cost effect.

Persistence Motives in Irrational Decisions to Complete a Boring Task

We explored a novel task paradigm where participants from the online work marketplace Amazon Mechanical Turk were given the choice to quit or continue an unfinished boring task for identical economic rewards. In Studies 1a and 1b, about half the participants chose to continue (corresponding to an average of 55 and 35 cents in foregone earnings). Participants’ self-reported reasons for continuing involved various types of persistence motives, reflecting a desire to persist or complete per se. Studies 2, 3a, 3b, and 3c ruled out the possibility that people continued because they enjoyed the task or believed there were additional rewards for continuing. Study 4 showed that the choice to quit/continue was associated with the manner in which the choice was presented (persistence test vs. decision-making test) and individual differences in dispositional persistence motives. The present data indicate that motivational forces independent of the focal reward may affect intertemporal decisions.

Suboptimal choice in nonhuman animals: rats commit the sunk cost error

The present experiments investigated the sunk cost error, an apparently irrational tendency to persist with an initial investment, in rats. This issue is of interest because some have argued that nonhuman animals do not commit this error. Two or three fixed-ratio (FR) response requirements were arranged on one lever, and an escape option was arranged on a second lever. The FRs were of different sizes, and escaping was the behavior of interest. Several variables that might influence the decision to persist versus escape were manipulated: the number of trials with different FR schedules in an experimental session (Exps. 1 and 2), effort to escape (Exp. 2), and the size of the larger FR (Exp. 3). The sunk cost error would result in never escaping, and the optimal strategy would be to escape from the larger FR. The main variable that determined persisting versus escaping was the size of the large FR. Rats that escaped from the large FR-apparently optimal behavior-did so at a suboptimal point, and hence committed the sunk cost error.

Decision-making heuristics and biases across the life span

We outline a contextual and motivational model of judgment and decision-making (JDM) biases across the life span. Our model focuses on abilities and skills that correspond to deliberative, experiential, and affective decision-making processes. We review research that addresses links between JDM biases and these processes as represented by individual differences in specific abilities and skills (e.g., fluid and crystallized intelligence, executive functioning, emotion regulation, personality traits). We focus on two JDM biases-the sunk-cost fallacy (SCF) and the framing effect. We trace the developmental trajectory of each bias from preschool through middle childhood, adolescence, early adulthood, and later adulthood. We conclude that life-span developmental trajectories differ depending on the bias investigated. Existing research suggests relative stability in the framing effect across the life span and decreases in the SCF with age, including in later life. We highlight directions for future research on JDM biases across the life span, emphasizing the need for process-oriented research and research that increases our understanding of JDM biases in people's everyday lives.

An investigation of the partial-assignment completion effect on students' assignment choice behavior

This study was designed to investigate the partial assignment completion effect. Seventh-grade students were given a math assignment. After working for 5 min, they were interrupted and their partially completed assignments were collected. About 20 min later, students were given their partially completed assignment and a new, control assignment that contained the same number of equivalent problems that were incomplete on their partially completed assignment. Students were told that they would have to complete an assignment but could choose which assignment they completed. Significantly more students chose their partially completed assignment. Theoretical and applied implications and directions for future research are discussed.