Przemysław Sawicki

Perception of randomness and predicting uncertain events

Using randomly generated sequences of binary events we asked participants to make predictions about the next event. It turned out that while predicting uncertain events, people do not behave unsystematically. Our research identifies four types of relatively consistent strategies for predicting uncertain binary events: a strategy immune to short-run sequential dependencies consisting of the persistent prediction of long-run majority events, hereafter called the long-run momentum strategy; a strategy immune to short-run sequential dependencies consisting of the persistent prediction of long-run minority events, called the long-run contrarian strategy; a strategy sensitive to short-run sequential dependencies consisting of the prediction of short-run majority events, called the short-run momentum strategy; and a strategy sensitive to short-run sequential dependencies consisting of the prediction of short-run minority events, called the short-run contrarian strategy. When the character of events remains unknown, the most common strategy is the short-run momentum strategy. With the increase of a perceived randomness of the situation, people tend more often to use the short-run contrarian strategy. People differ in their general beliefs about the continuation or reversal of a trend in various natural and social processes. Trend believers, when facing sequences of binary events commonly perceived as random, tend to use momentum strategies, whereas those who believe in the trends reversal tend to use contrarian strategies.

Affective and Cognitive Factors Influencing Sensitivity to Probabilistic Information

In study 1 different groups of female students were randomly assigned to one of four probabilistic information formats. Five different levels of probability of a genetic disease in an unborn child were presented to participants (within-subject factor). After the presentation of the probability level, participants were requested to indicate the acceptable level of pain they would tolerate to avoid the disease (in their unborn child), their subjective evaluation of the disease risk, and their subjective evaluation of being worried by this risk. The results of study 1 confirmed the hypothesis that an experience-based probability format decreases the subjective sense of worry about the disease, thus, presumably, weakening the tendency to overrate the probability of rare events. Study 2 showed that for the emotionally laden stimuli, the experience-based probability format resulted in higher sensitivity to probability variations than other formats of probabilistic information. These advantages of the experience-based probability format are interpreted in terms of two systems of information processing: the rational deliberative versus the affective experiential and the principle of stimulus-response compatibility.

Can taking the perspective of an expert debias human decisions?The case of risky and delayed gains

In several previously reported studies, participants increased their normative correctness after being instructed to think hypothetically, specifically taking the perspective of an expert or researcher (Beatty and Thompson, 2012; Morsanyi and Handley, 2012). The goal of this paper was to investigate how this manipulation affects risky or delayed payoffs. In two studies, participants (n = 193) were tested online (in exchange for money) using the adjusting procedure. Individuals produced certain/immediate equivalents for risky/delayed gains. Participants in the control group were solving the problem from their own perspective, while participants in the experimental group were asked to imagine “what would a reliable and honest advisor advise them to do.” Study 1 showed that when taking the perspective of an expert, participants in experimental group became more risk aversive compared to participants in the control group. Additionally, their certain equivalents diverged from the expected value to a greater extent. The results obtained from the experimental group in Study 2 suggest that participants became less impulsive, which means they tried to inhibit their preferences. This favors the explanation, which suggests that the perspective shift forced individuals to override their intuitions with the social norms. Individuals expect to be blamed for impatience or risk taking thus expected an expert to advise them to be more patient and risk aversive.

Introducing conjoint analysis method into delayed lotteries studies: its validity and time stability are higher than in adjusting

The delayed lotteries are much more common in everyday life than are pure lotteries. Usually, we need to wait to find out the outcome of the risky decision (e.g., investing in a stock market, engaging in a relationship). However, most research has studied the time discounting and probability discounting in isolation using the methodologies designed specifically to track changes in one parameter. Most commonly used method is adjusting, but its reported validity and time stability in research on discounting are suboptimal. The goal of this study was to introduce the novel method for analyzing delayed lotteries—conjoint analysis—which hypothetically is more suitable for analyzing individual preferences in this area. A set of two studies compared the conjoint analysis with adjusting. The results suggest that individual parameters of discounting strength estimated with conjoint have higher predictive value (Study 1 and 2), and they are more stable over time (Study 2) compared to adjusting. We discuss these findings, despite the exploratory character of reported studies, by suggesting that future research on delayed lotteries should be cross-validated using both methods.

You Cannot be Partially Pregnant: A Comparison of Divisible and Nondivisible Outcomes in Delay and Probability Discounting Studies

Research by The Psychological Record, 64(3), 433–440. doi:10.1007/s40732-014-0052-9, (2014) demonstrated the novel finding that the magnitude effect for medical outcomes does not reverse across delay and probability discounting as it does for monetary outcomes. We suggest that a possible reason for the lack of a reverse magnitude effect in nonmonetary outcomes is incomparable divisibility of discounted alternatives.To test whether the lack of a reverse magnitude effect in probability discounting of medical outcomes is due to incomparable divisibility of treatment effects, 4 studies were conducted. In the replication study, the effect observed by The Psychological Record, 64(3), 433–440. doi:10.1007/s40732-014-0052-9, (2014) was marginally not significant, although it was directionally consistent with their prediction of steeper discounting of small medical outcomes (as compared to large, defined as brain cancer) both in time and probability discounting. Our manipulation by substituting a divisible outcome (body paralysis) for an indivisible one (brain cancer) did not, however, bring expected results. We discuss the explanations and possible implications of introduced division for divisible and nondivisible medical outcomes.

Side Effects in Time Discounting Procedures: Fixed Alternatives Become the Reference Point

Typical research on intertemporal choice utilizes a two-alternative forced choice (2AFC) paradigm requiring participants to choose between a smaller sooner and larger later payoff. In the adjusting-amount procedure (AAP) one of the alternatives is fixed and the other is adjusted according to particular choices made by the participant. Such a method makes the alternatives unequal in status and is speculated to make the fixed alternative a reference point for choices, thereby affecting the decision made. The current study shows that fixing different alternatives in the AAP influences discount rates in intertemporal choices. Specifically, individuals’ (N = 283) choices were affected to just the same extent by merely fixing an alternative as when choices were preceded by scenarios explicitly imposing reference points.

Cognitive Reflection Effects on Time Discounting

In this work, we investigated individual differences in cognitive reflection effects on delay discounting – a preference for smaller sooner over larger later payoff. People are claimed to prefer more these alternatives they considered first – so-called reference point – over the alternatives they considered later. Cognitive reflection affects the way individuals process information, with less reflective individuals relying predominantly on the first information they consider, thus, being more susceptible to reference points as compared to more reflective individuals. In Experiment 1, we confirmed that individuals who scored high on the Cognitive Reflection Test discount less strongly than less reflective individuals, but we also show that such individuals are less susceptible to imposed reference points. Experiment 2 replicated these findings additionally providing evidence that cognitive reflection predicts discounting strength and (in)dependency to reference points over and above individual difference in numeracy.

Correction: Side Effects in Time Discounting Procedures: Fixed Alternatives Become the Reference Point

[This corrects the article DOI: 10.1371/journal.pone.0165245.].