PREFERENCE REVERSALS DUE TO MYOPIC DISCOUNTING OF DELAYED REWARD

Abstract— A basic stationarity axiom of economic theory assumes stable preference between two deferred goods separated by a fixed time. To test this assumption, we offered subjects choices between delayed rewards, while manipulating the delays to those rewards. Preferences typically reversed with changes in delay, as predicted by hyperbolic discounting models of impulsiveness. Of 36 subjects, 34 reversed preference from a larger, later reward to a smaller, earlier reward as the delays to both rewards decreased. We conclude that the stationarity axiom is not appropriate in models of human choice.     

Delay-discounting probabilistic rewards: Rates decrease as amounts increase

The independence of delay-discounting rate and monetary reward size was tested by offering subjects (N = 621) a series of choices between immediate rewards and larger, delayed rewards. In contrast to previous studies, in which hypothetical rewards have typically been employed, subjects in the present study were entered into a lottery in which they had a chance of actually receiving one of their choices. The delayed rewards were grouped into small ($30–$35), medium ($55–$65), and large amounts ($70–$85). Using a novel parameter estimation procedure, we estimated discounting rates for all three reward sizes for each subject on the basis of his/her pattern of choices. The data indicated that the discounting rate is a decreasing function of the size of the delayed reward (p < .0001), whether hyperbolic or exponential discounting functions are assumed. In addition, a reliable gender difference was found (p = .005), with males discounting at higher rates than females, on average.     

The interactive effect of introversion-extraversion with caffeine induced arousal on verbal performance

In a test of the arousal hypothesis of introversion-extraversion, subjects were pre- and post-tested on practice Graduate Record Examination verbal performance items while administered caffeine at either 0, 2, or 4 mg/kg of body weight. Introverts increased dramatically in performance between the 0 and 2 mg/kg conditions and then decreased even more dramatically between the 2 and 4 mg/kg conditions. Extraverts showed decrements in performance at the 0 mg/kg level, improved slightly at the 2 mg/kg level, and showed marked improvement at the 4 mg/kg level. Further analyses revealed that introverts increased in both speed and accuracy at low levels of stimulation but then decreased in both at higher levels of stimulation. Extraverts showed continued increases in speed and accuracy across the increasing arousal levels.     

A comprehensive measure of attitudes and behaviour: Development of the Support for Gender Equality among Men Scale

In this article, we develop and validate the 16-item Support for Gender Equality among Men Scale across four studies. Drawing on exploratory (Study 1, n = 322) and confirmatory (Study 2, n = 358; Study 4, n = 192) factor analysis, we determine a two-factor structure: public and domestic support for gender equality. In Study 3 (n = 146) and Study 4, we validate the scale by establishing its relationship with, among others, several prominent measures of sexism, a behavioural measure, and social desirability. The scale fills a psychometric gap in the literature: To date, no validated measure of support for gender equality, measuring both attitudes and behavioural intentions and focusing specifically on men, exists. Considering the recent increase in interest in men as allies of the feminist movement the scale functions as a useful tool to explore the topic in depth in future research.     

Reviews: Books, Art

POLITICS ON THE COUCH: CITIZENSHIP AND THE INTERNAL LIFE. By Andrew Samuels, 235 pp. New York: Karnac (Other Press). $16.00. MARTHA, MARTHA: HOW CHRISTIANS WORRY. By Elaine Leong Eng, M.D. Binghamton, NY: Haworth Press, Inc., 2000. $14.95. SPILT MILK: PERINATAL LOSS AND BREAKDOWN. Edited by Joan Raphael-Leff. 100 pp. London: Institute of Psychoanalysis, 2000. MOTHERHOOD AND SEXUALITY. By Marie Langer, 305 pp. New York: Other Press, 2000. $30.00. BRANCHING STREAMS FLOW IN THE DARKNESS: ZEN TALKS ON THE SANDOKAI. By S. Suzuki. Eds: M. Weitsman and M. Wegner. 193 pp. Berkeley, CA: University of California Press. $22.50. RESTORED HARMONY: AN EVIDENCE BASED APPROACH FOR INTEGRATING TRADITIONAL CHINESE MEDICINE INTO COMPLEMENTARY CANCER CARE. By Stephen Sagar, MD. xviii + 134 pp. Hamilton, Ontario, Canada: Dreaming Dragonfly Communications, 2001. $19.95 (US); $29.95 (Can.), paperback. (ISBN: 0-9689488-0-4). CHIYO-NI, WOMAN HAIKU MASTER. By Patricia Donegan and Yoshie Ishibashi, 184 pp. Boston: Charles E. Tuttle Co., 1998. $16.95. THE METAPHYSICAL CLUB: A STORY OF IDEAS IN AMERICA. By Louis Menand, 442 pp. New York: Farrrar, Straus, and Giroux, 2001. $27.00. BUDDHISM WITHOUT BELIEFS: A CONTEMPORARY GUIDE TO AWAKENING. By Stephen Bachelor, 127 pp. Riverhead Books, 1997. $21.95. Video Art is Dead, Long Live Video Art     

Is emotional intelligence an advantage? An exploration of the impact of emotional and general intelligence on individual performance

Emotional intelligence is an increasingly popular consulting tool. According to popular opinion and work-place testimonials, emotional intelligence increases performance and productivity; however, there has been a general lack of independent, systematic analysis substantiating that claim. The authors investigated whether emotional intelligence would account for increases in individual cognitive-based performance over and above the level attributable to traditional general intelligence. The authors measured emotional intelligence with the Multifactor Emotional Intelligence Scale (MEIS; J. D. Mayer, P. Salovey, & D. R. Caruso, 1997). As measured by the MEIS, overall emotional intelligence is a composite of the 3 distinct emotional reasoning abilities: perceiving, understanding, and regulating emotions (J. D. Mayer & P. Salovey, 1997). Although further psychometric analysis of the MEIS is warranted, the authors found that overall emotional intelligence, emotional perception, and emotional regulation uniquely explained individual cognitive-based performance over and beyond the level attributable to general intelligence.     

Heroin addicts have higher discount rates for delayed rewards than non-drug-using controls

Fifty-six heroin addicts and 60 age-matched controls were offered choices between monetary rewards ($11-$80) available immediately and larger rewards ($25-$85) available after delays ranging from 1 week to 6 months. Participants had a 1-in-6 chance of winning a reward that they chose on one randomly selected trial. Delay-discounting rates were estimated from the pattern of participants' choices. The discounting model of impulsiveness (Ainslie, 1975) implies that delay-discounting rates are positively correlated with impulsiveness. On average, heroin addicts' discount rates were twice those of controls (p = .004), and discount rates were positively correlated with impulsivity as measured by self-report questionnaires (p < .05). The results lend external validity to the delay-discounting rate as a measure of impulsiveness, a characteristic associated with substance abuse.     

Income Source and Race Effects on New-Neighbor Evaluations1

Two studies investigated the effect of income source and race on ratings of and objections to potential neighbors. Equivalent amounts of income from different sources included work only, work and public assistance, or work and a small inheritance. The race variable included African American, European American, or Hispanic. Subjects for Study 1 were undergraduate psychology students. Subjects for Study 2 were homeowners. Class bias was not a symbolic way to express race bias. There was a clear distinction between class bias and race bias in expression and function. Results indicate that class bias was used when subjects gave ratings of new neighbors. These biased ratings do not correlate with measures of racism. Furthermore, results indicate that objections to the new neighbors were more frequent for those gaining income from sources other than work. The findings indicate that class prejudice based on income source is primary and openly expressed, whereas racial prejudice does not appear as an important contributing factor in this context.