Effects of symptom presentation order on perceived disease risk

People are quick to perceive meaningful patterns in the co-occurrence of events. We report two studies exploring the effects of streaks in symptom checklists on perceived personal disease risk. In the context of these studies, a streak is a sequence of consecutive items on a list that share the characteristic of being either general or specific. We identify a psychological mechanism underlying the effect of streaks in a list of symptoms and show that the effect of streaks on perceived risk varies with the length of the symptom list. Our findings reveal a tendency to infer meaning from streaks in medical and health decision making. Participants perceived a higher personal risk of having an illness when presented with a checklist in which common symptoms were grouped together than when presented with a checklist in which these same symptoms were separated by rare symptoms. This research demonstrates that something as arbitrary as the order in which symptoms are presented in a checklist can affect perceived risk of disease.     

The hot hand exists in volleyball and is used for allocation decisions

The "hot hand" belief in sports refers to the conviction that a player has a higher chance of making a shot after two or three successful shots than after two or three misses (resulting in "streaks"). This belief is usually considered a cognitive fallacy, although it has been conjectured that in basketball the defense will attack a "hot" player and prevent streaks from occurring. To address this argument, we provide the first study on the hot hand in volleyball, where the net limits direct defensive counterstrategies, meaning that streaks can more likely emerge if a player is hot. We first establish that athletes believe in the hot hand in volleyball (Study 1A). Analyzing the top 26 first-division players, we then show that streaks do exist for half of the players (Study 1B). Coaches can detect players' performance variability and use it to make strategic decisions (Study 2A). Playmakers are also sensitive to streaks and rely on them when deciding to whom to allocate the ball (Study 2B). We conclude that for volleyball the hot hand exists, coaches and playmakers are able to detect it, and playmakers tend to use it "adaptively," which results in more hits for a team.     

Perception of randomness: On the time of streaks

People tend to think that streaks in random sequential events are rare and remarkable. When they actually encounter streaks, they tend to consider the underlying process as non-random. The present paper examines the time of pattern occurrences in sequences of Bernoulli trials, and shows that among all patterns of the same length, a streak is the most delayed pattern for its first occurrence. It is argued that when time is of essence, how often a pattern is to occur (mean time, or, frequency) and when a pattern is to first occur (waiting time) are different questions and bear different psychological relevance. The waiting time statistics may provide a quantitative measure to the psychological distance when people are expecting a probabilistic event, and such measure is consistent with both of the representativeness and availability heuristics in people’s perception of randomness. We discuss some of the recent empirical findings and suggest that people’s judgment and generation of random sequences may be guided by their actual experiences of the waiting time statistics.     

Perception of randomness: On the time of streaks

People tend to think that streaks in random sequential events are rare and remarkable. When they actually encounter streaks, they tend to consider the underlying process as non-random. The present paper examines the time of pattern occurrences in sequences of Bernoulli trials, and shows that among all patterns of the same length, a streak is the most delayed pattern for its first occurrence. It is argued that when time is of essence, how often a pattern is to occur (mean time, or, frequency) and when a pattern is to first occur (waiting time) are different questions and bear different psychological relevance. The waiting time statistics may provide a quantitative measure to the psychological distance when people are expecting a probabilistic event, and such measure is consistent with both of the representativeness and availability heuristics in people’s perception of randomness. We discuss some of the recent empirical findings and suggest that people’s judgment and generation of random sequences may be guided by their actual experiences of the waiting time statistics.     

Carry on winning: The gamblers’ fallacy creates hot hand effects in online gambling

People suffering from the hot-hand fallacy unreasonably expect winning streaks to continue whereas those suffering from the gamblers’ fallacy unreasonably expect losing streaks to reverse. We took 565,915 sports bets made by 776 online gamblers in 2010 and analyzed all winning and losing streaks up to a maximum length of six. People who won were more likely to win again (apparently because they chose safer odds than before) whereas those who lost were more likely to lose again (apparently because they chose riskier odds than before). However, selection of safer odds after winning and riskier ones after losing indicates that online sports gamblers expected their luck to reverse: they suffered from the gamblers’ fallacy. By believing in the gamblers’ fallacy, they created their own hot hands.     

Heuristics as beliefs and as behaviors: the adaptiveness of the "hot hand"

and analyzed reasoning by asking: what are the reasoner's goals? This emphasizes the adaptiveness of behavior rather than whether a belief is normative. Belief in the "hot hand" in basketball suggests that players experiencing streaks should be given more shots, but this has been seen as a fallacy due to failure to find dependencies between players' shots. Based on their findings, I demonstrate by Markov modeling and simulation that streaks are valid allocation cues for deciding who to give shots to, because this behavior achieves the team goal of scoring more. Empirically I show that this adaptive heuristic is supported by the fallacious belief in dependency, more so as skill level increases. I extend the theoretical analysis to identify general conditions under which following streaks should be beneficial. Overall, this approach illustrates the advantages of analyzing reasoning in terms of adaptiveness.     

Motion impressions enhanced by converging motion lines

We investigated how motion lines drawn in the background of a running human silhouette affect motion impressions of a runner in a static image. Observers evaluated the strength and direction of motion impression. The results show that parallel lines do not enhance frontoparallel motion impressions, while converging lines do so in an in-depth direction. This is a counter-example to the hypothesis that motion lines in the background represent motion streaks of the background when one visually tracks a moving object.     

‘Put Your Money Where Your Mouth Is!’: Effects of Streaks on Confidence and Betting in a Binary Choice Task

Human choice under uncertainty is influenced by erroneous beliefs about randomness. In simple binary choice tasks, such as red/black predictions in roulette, long outcome runs (e.g. red, red, red) typically increase the tendency to predict the other outcome (i.e. black), an effect labeled the “gambler's fallacy.” In these settings, participants may also attend to streaks in their predictive performance. Winning and losing streaks are thought to affect decision confidence, although prior work indicates conflicting directions. Over three laboratory experiments involving red/black predictions in a sequential roulette task, we sought to identify the effects of outcome runs and winning/losing streaks upon color predictions, decision confidence and betting behavior. Experiments 1 (n = 40) and 3 (n = 40) obtained trial‐by‐trial confidence ratings, with a win/no win payoff and a no loss/loss payoff, respectively. Experiment 2 (n = 39) obtained a trial‐by‐trial bet amount on an equivalent scale. In each experiment, the gambler's fallacy was observed on choice behavior after color runs and, in experiment 2, on betting behavior after color runs. Feedback streaks exerted no reliable influence on confidence ratings, in either payoff condition. Betting behavior, on the other hand, increased as a function of losing streaks. The increase in betting on losing streaks is interpreted as a manifestation of loss chasing; these data help clarify the psychological mechanisms underlying loss chasing and caution against the use of betting measures (“post‐decision wagering”) as a straightforward index of decision confidence. © 2014 The Authors. Journal of Behavioral Decision Making published by John Wiley & Sons Ltd.     

Beliefs about the "hot hand" in basketball across the adult life span

Many people believe in streaks. In basketball, belief in the "hot hand" occurs when people think a player is more likely to make a shot if they have made previous shots. However, research has shown that players' successive shots are independent events. To determine how age would impact belief in the hot hand, we examined this effect across the adult life span. Older adults were more likely to believe in the hot hand, relative to younger and middle-aged adults, suggesting that older adults use heuristics and potentially adaptive processing based on highly accessible information to predict future events. (PsycINFO Database Record (c) 2012 APA, all rights reserved).     

An analysis of streaky performance on the LPGA Tour

A study investigated the occurrence of streakiness among professional golfers on the LPGA Tour. For players, individually or as a group, the findings showed a significant tendency for players' par or better rounds to occur together and for players' above par rounds to occur together. However, the observed streakiness in players' scores was related to the difficulty of golf courses rather than to any inherent disposition of players' performances to be streaky. The results replicated those findings found on the PGA Tour and Senior PGA Tour.     

Decision‐making Under Uncertainty in the Cash Cab

Television game shows have long been used to analyze risk‐taking behavior. We used episodes of Cash Cab to investigate how a variety of pre‐game and in‐game factors affected contestants' decisions to accept or reject a double‐or‐nothing gamble offered at the end of the game. As expected, the analysis confirmed the standard influences of gender, age, and group size on the willingness to accept the gamble. More interestingly, however, the data suggested that contestants also used in‐game experiences to update their subjective probability of success when considering the final gamble. Surprisingly, contestants did not appear to use correct performance (e.g., number correct, and streaks of correct) when updating, but the number and distribution of highly confident and correct responses were important when assessing the final gamble. Copyright © 2013 John Wiley & Sons, Ltd.     

The role of priming in conjunctive visual search

To assess the role of priming in conjunctive visual search tasks, we systematically varied the consistency of the target and distractor identity between different conditions. Search was fastest in the standard conjunctive search paradigm where identities remained constant. Search was slowest when potential target identity varied predictably for each successive trial (the 'switch' condition). The role of priming was also demonstrated on a trial-by-trial basis in a 'streak' condition where target and distractor identity was unpredictable yet was consistent within streaks. When the target to be found was the same for a few trials in a row, search performance became similar to that when the potential target was the same on all trials. A similar pattern was found for the target absent trials, suggesting that priming is based on the whole search array rather than just the target in each case. Further analysis indicated that the effects of priming are sufficiently strong to account for the advantage seen for the conjunctive search task. We conclude that the role of priming in visual search is underestimated in current theories of visual search and that differences in search times often attributed to top-down guidance may instead reflect the benefits of priming.     

Motivated reasoning in the prediction of sports outcomes and the belief in the “hot hand”

The present paper explores the role of motivation to observe a certain outcome in people’s predictions, causal attributions, and beliefs about a streak of binary outcomes (basketball scoring shots). In two studies we found that positive streaks (points scored by the participants’ favourite team) lead participants to predict the streak’s continuation (belief in the hot hand), but negative streaks lead to predictions of its end (gambler’s fallacy). More importantly, these wishful predictions are supported by strategic attributions and beliefs about how and why a streak might unfold. Results suggest that the effect of motivation on predictions is mediated by a serial path via causal attributions to the teams at play and belief in the hot hand.     

From a fixation on sports to an exploration of mechanism: The past,present, and future of hot hand research

We review the literature on the hot hand fallacy by highlighting the positive and negative aspects of hot hand research over the past 20 years, and suggesting new avenues of research. Many researchers have focused on criticising Gilovich et al.'s claim that the hot hand fallacy exists in basketball and other sports, instead of exploring the general implications of the hot hand fallacy for human cognition and probabilistic reasoning. Noting that researchers have shown that people perceive hot streaks in a gambling domain in which systematic streaks cannot possibly exist, we suggest that researchers have paid too much attention to investigating the independence of outcomes in various sporting domains. Instead, we advocate a domain-general mechanistic approach to understanding the hot hand fallacy, and conclude by suggesting approaches that might refocus the literature on the important general implications of the hot hand fallacy for human probabilistic reasoning.     

The intentional mind and the hot hand: Perceiving intentions makes streaks seem likely to continue

People can appear inconsistent in their intuitions about sequences of repeated events. Sometimes people believe such sequences will continue (the “hot hand”), and sometimes people believe they will reverse (the “gambler’s fallacy”). These contradictory intuitions can be partly explained by considering the perceived intentionality of the agent generating the streak. The intuition that streaks will continue (reverse) should emerge in contexts involving agents that are perceived to be intentional (unintentional), and should be most common among those who are most inclined to attribute intentions to other agents. Four studies support these predictions, identifying both situational and dispositional determinants of the perceived continuity of streaks. Discussion focuses on the foundational nature of intentionality for perceptions of interdependence between events, the relationship between these findings and existing theoretical accounts, and the inverse possibility that people use perceptions of streakiness as a cue for an agent’s intentionality.     

Peaking at the right time: Perceptions,expectations, and effects

We explore the concept of peaking at the right time. Study 1 is a content analysis of 325 National Football League articles identifying four key triggers that prompt proclamations of peaking at the right time: turnarounds, impressive prior events, winning streaks, and out-ofs. Study 2 experimental results reveal that turnarounds most strongly impact perceptions of peaking at the right time, anticipated performance, and expectations faced. However, nuanced differences occur across two time periods during the season. Studies 1 and 2 also indicate that observers expect teams to win their next games more often than actually happens. Study 3 demonstrates that teams prepare harder and make riskier game plans when their next opponent is peaking at the right time. Study 4 suggests that individuals more strongly desiring to peak at the right time than others will value various factors differently at different time points when envisioning upcoming seasons.     

Visual orientation by motion-produced blur patterns: Detection of divergence

Blur patterns are physiological “streaks” of photochemical and neural activity that occur whenever an observer and his visual environment are in relative motion. When retinal velocities are high, the impression of visual “flow” gives way to one of a field of “blur lines” whose patterns are rich with information about the motions and the optical textures that produced them. Simulated blur patterns were produced and thresholds measured for the detection of divergence at nine retinal loci. Sensitivity was somewhat greater in the central retina. Thresh-olds remained the same despite variations in pattern velocity, number of elements, and the presence or absence of an internal velocity gradient. Observers were able to orient above-threshold patterns, but consistently underestimated the amount of slant.     

The rule of three: How the third event signals the emergence of a streak

It is well established that people perceive streaks where they do not exist. However, little is known about what constitutes a streak in the mind of an observer. This paper proposes that the third repeat event in a sequence is pivotal to the subjective belief that a streak is occurring. In five studies, we find direct and indirect evidence that perceived streakiness plateaus with the third repeat outcome in a sequence. The evidence to support this rule of three comes from various domains, including: observation of randomly determined probabilistic outcomes, investment decisions in response to performance histories, and basketball shooting percentages.     

Randomness in retrospect: Exploring the interactions between memory and randomness cognition

People tend to believe that sequences of random events produce fewer and shorter streaks than is actually the case. Although this error has been demonstrated repeatedly and in many forms, nearly all studies of randomness cognition have focused on how people think about random events occurring in the present or future. This article examines how our biased beliefs about randomness interact with properties of memory to influence our judgments about and memory for past random events. We explore this interaction by examining how beliefs about randomness affect our memory for random events and how certain properties of memory alter our tendency to categorize events as random. Across three experiments, we demonstrate an interaction between randomness cognition and three well-established but distinct properties of memory: (1) the reconstructive nature of memory, (2) primacy and recency effects, and (3) duration neglect. Theoretical and practical implications are discussed.     

Hearing From Both Sides: Differences Between Liberal and Conservative Attitudes Toward Scientific and Experiential Evidence

Two studies examined how political ideology relates to attitudes towards opposing scientific and nonscientific perspectives on apolitical topics. Participants read an article excerpt containing quotes from a researcher debunking a common misconception, such as the existence of lucky streaks in games of chance. They also read the perspective of someone who rejected the researcher in favor of personal experience, either in the form of a quote in the article from a relevant professional (e.g., a casino manager, Study 1) or a comment from a purported previous respondent with no clear expertise (Study 2). In both studies, conservatives, compared to liberals, evaluated the views of the scientist and the person rejecting the science as closer in legitimacy. Differences in evaluation of the science rejecter were mediated by conservatives' heightened intuitive thinking. By spotlighting how partisans evaluate nonscientific perspectives alongside science and by focusing on apolitical topics, these results bring new clarity to the debate on whether conservatives are more biased than liberals in attitudes towards science.