Investigating the roots of the favourite–longshot bias: an analysis of decision making by supply‐ and demand‐side agents in parallel betting markets

This paper offers new insights into the behavioural origins of the ‘favourite–longshot’ bias — an established feature of betting markets, whereby longshots win less often than the subjective probabilities imply and favourites more often. A number of alternative explanations has been offered for this phenomenon but the main debate focuses on whether it is caused by the behaviour of those supplying betting markets (bookmakers) or of the demand‐side agents in these markets (bettors) . This study analyses a new data source which offers detailed information for a large sample of recent UK horseraces on decision‐making behaviour within the parimutuel and the parallel bookmaker‐based betting markets. The results offer strong evidence for the existence of the ‘favourite–longshot’ bias in bookmaker‐based markets, with a corresponding absence of such an effect in the parimutuel case. These results offer support for the view that the origins of the ‘favourite–longshot’ bias lie principally in the decisions of bookmakers rather than in the decisions of bettors. Copyright © 2000 John Wiley & Sons, Ltd.     

Seek and ye shall find: test results are what you hypothesize they are

Expert clinicians were given batteries of psychodiagnostic test results (Rorschach, TAT, Draw-A-Person, Bender-Gestalt, Wechsler) to analyze. For half, a battery came along with a suggestion that the person suffers from Borderline Personality disorder, and for half, that battery was accompanied by a suggestion that he suffers from Paranoid Personality disorder. In Study 1, the suggestion was made indirectly, through a background story that preceded the test results. In Study 2, the suggestion was made directly, by the instructions given. The experts saw in the tests what they hypothesized to be there. In particular, the target diagnoses were rated higher when they were hypothesized than when they were not. Copyright © 1998 John Wiley & Sons, Ltd.     

Notes on the weighting biases in value trees

The variation in the structure of value trees can have undesirable effects on the attribute weights. Earlier experiments suggest that an attribute receives a higher weight if it is presented at an upper level in a value tree or if it is split into subattributes. Here we show that it is flawed to make conclusions about the biases at the individual level based on the averages of weights across large groups of subjects. Averages do not describe individual behavior. Furthermore, the averages of weights tend to approach even weights. By using the data from earlier experiments we illustrate how the averaging can produce different phenomena. We also show that the use of weights based on the rank order of attributes only can easily lead to biases when the structure of a value tree is changed. © 1998 John Wiley & Sons, Ltd.     

Similarity and reluctance to trade

Previous research has shown that after decision makers are endowed with an object, they are reluctant to trade it for an alternative item. This endowment effect can be explained by loss aversion, the tendency to weight losses more heavily than gains. Consequently, there is no reluctance to trade when no true loss is involved. Four studies investigated whether reluctance to trade declines when the trade involves less of a loss—specifically, when one item is traded for another very similar item. Three experiments did not reveal a relation between willingness to trade and the similarity between the two items being traded. A fourth experiment, however, indicated that subjects were quite willing to trade for an identical item, less willing to trade for a similar item, and even less willing to trade for a dissimilar item. Thus, reluctance to trade decreased as the similarity between the endowment and the alternative increased. This result suggests that loss aversion is a function not only of the item being lost but also of the trade itself—that is, of the relation between the two items being traded. © 1998 John Wiley & Sons, Ltd.     

Evidence for a young adult face bias in accuracy and consensus of age estimates

Adults' face processing may be specialized for the dimensions of young adult faces. For example, young and older adults exhibit increased accuracy in normality judgments and greater agreement in attractiveness ratings for young versus older adult faces. The present study was designed to examine whether there is a similar young adult face bias in facial age estimates. In Experiment 1, we created a face age continuum by morphing an averaged young adult face with an averaged older adult face in 5% increments, for a total of 21 faces ranging from 0 to 100% old. Young and older adults estimated facial age for three stimulus age categories [young (morphs 0–30%), middle‐aged (morphs 35–65%), and older adult (morphs 70–100%)]. Both age groups showed the least differentiation in age estimates for young adult faces, despite showing greater consensus across participants in estimates for young faces. In Experiment 2, young and older adults made age estimates for individual young and older adult identities. Both age groups were more accurate and showed greater consensus in age estimates for young faces. Collectively, these results provide evidence for a bias in processing young adult faces beyond that which is often observed in recognition and normality/attractiveness judgment tasks.     

Philosophy’s Diversity Problem

This paper explores the underrepresentation of women and minorities in academic philosophy. Specifically, it focuses on why, given the relatively even male/female ratio at undergraduate level, women are underrepresented at every level above this. It addresses some of the misconceptions and myths surrounding women in philosophy, including those surrounding the discussion of the different‐intuition hypothesis. It also explores the ways in which feminist research in philosophy is subject to marginalisation as a result of systematic exclusionary practices typical of the dominant culture of justification within traditional philosophy. It argues for the necessity of an intersectional approach, and the importance of taking seriously the psychological and sociological analysis of underrepresentation, in order to improve both the experience and the representation of women and other minorities at all levels of professional philosophy, as well as of the discipline as a whole.     

With respect to prejudice

The basic assumptions of psychotherapy must necessarily reflect the cultural orientations and dilemmas of the western societies, and historical periods, in which these originated. This paper considers how the racialised biases of that period, namely, the era of European domination built upon the conquest, colonisation and enslavement of non‐European peoples, may linger in psychotherapeutic training and practice today. This not only limits the potential usefulness of the discipline in the multicultural populations of the west, but also risks it being read as covert neo‐colonialism in the ‘non‐west’. In a world that ever more clearly demonstrates the human costs of prejudice psychotherapists in general, and Jungians in particular, might wish to consider how, wittingly or otherwise, they maintain prejudiced ways of thinking. This paper examines material from the author's professional and personal experience, using literature that lies outside the specifically Jungian canon, to expose how such bias might work.     

The longitudinal relationships of interpersonal openness trait,hostility, and hostile attribution bias

While the relationship between personality, hostility, and hostile attribution bias (HAB) has been explored in previous studies, their longitudinal relationship is unclear, and no related study has utilized the indigenous Chinese personality. This research explored the longitudinal relationships of interpersonal openness (IO; an indigenous Chinese personality construct), hostility, and HAB. The 942 valid participants (38.5% male, mean age = 20.83, standard deviation = 1.04) were from six different provinces in China. Measurements were completed on two separate occasions (Times 1 and 2), with a 6-month interval. Results showed that IO has longitudinal effects on hostility, after controlling for the Big Five, and HAB could be longitudinally predicted by IO and hostility as well. Moreover, hostility served as a mediator in the relationship between IO and HAB. These results suggest that IO can affect the development of hostility and HAB, and some indigenous Chinese personality factors may complement Western personality theories.     

Variability of attention bias in socially anxious adolescents: differences in fixation duration toward adult and adolescent face stimuli

Prior research on attention bias in anxious youth, often utilising a visual dot probe task, has yielded inconsistent findings, which may be due to how bias is assessed and/or variability in the phenomenon. The present study utilises eye gaze tracking to assess attention bias in socially anxious adolescents, and explores several methodological and within-subject factors that may contribute to variability in attention bias. Attention bias to threat was measured in forty-two treatment-seeking adolescents (age 12–16 years) diagnosed with Social Anxiety Disorder. Bias scores toward emotional stimuli (vigilant attention) and bias scores away from emotional stimuli (avoidant attention) were explored. Bias scores changed between vigilance and avoidance within individuals and over the course of stimulus presentation. These differences were not associated with participant characteristics nor with self-reported social anxiety symptoms. However, clinician rated severity of social anxiety, explained a significant proportion of variance in the bias scores for adult, but not the adolescent, stimuli. Variability in attention bias among socially anxious adolescents is common and varies as a function of stimulus duration and type. Results may inform stimulus selection for future research.     

Negativity bias in false memory: moderation by neuroticism after a delay

The negativity bias is the tendency for individuals to give greater weight, and often exhibit more rapid and extreme responses, to negative than positive information. Using the Deese-Roediger-McDermott illusory memory paradigm, the current study sought to examine how the negativity bias might affect both correct recognition for negative and positive words and false recognition for associated critical lures, as well as how trait neuroticism might moderate these effects. In two experiments, participants studied lists of words composed of semantic associates of an unpresented word (the critical lure). Half of the lists were comprised of positive words and half were comprised of negative words. As expected, individuals remembered negative list words better than positive list words, consistent with a negativity bias in correct recognition. When tested immediately (Experiment 1), individuals also exhibited greater false memory for negative versus positive critical lures. When tested after a 24-hr delay (Experiment 2), individuals higher in neuroticism maintained greater false memory for negative versus positive critical lures, but those lower in neuroticism showed no difference in false memory between negative and positive critical lures. Possible mechanisms and implications for mental health disorders are discussed.