Temporal patterns of sexual behavior in rabbits as determined by an automatic recording technique

Sexual behavior between rabbits was automatically recorded by means of electrodes attached externally to the unrestrained animals. Current flowed only when the animals came into physical contact; the duration and amplitude of the current flow provided a means of automatic differentiation between sexual and other types of physical contact. Various temporal aspects of sexual behavior were revealed: (1) copulation was preceded by a series of thrusts that occurred at a constant frequency of 13 to 14 thrusts per sec; (2) the duration of a copulation was about 1.5 sec and could be as brief as 0.3 sec; (3) copulation was much more likely during the hours between dusk and dawn despite constant illumination; (4) copulations occurred in groups or “runs” characterized by many copulations within a few hours; (5) each run began with a high rate of copulation that often decreased over time; (6) between runs, several hours or days passed with little or no sexual activity; and (7) a run of copulations was noted at the end of every 16- to 20-day period (which corresponds to the known period of pseudopregnancy in rabbits) whether or not other runs occurred within this period.     

Influence of Future Choice Importance and Arousal upon the Halo Effect

Two determinants of the magnitude of the influence of anticipated choice on the halo effect are investigated: importance of future choice and arousal. Male subjects ranked photographs on positive personality traits. Half of the photographs were of persons about which they anticipated making a choice. In confirmation of the hypotheses, (a) the intercorrelation of the rankings was greater for the choice photographs than for the nonchoice photographs when the subjects anticipated an important choice, but not when they anticipated an unimportant choice; and (b) the intercorrelation was greater for the choice photographs than for the nonchoice photographs when the subjects were aroused by caffeine and uninformed as to the source of their arousal, but not when they were informed as to the source of their arousal or not aroused.     

The reappearance hypothesis revisited: Recurrent involuntary memories after traumatic events and in everyday life

Recurrent involuntary memories are autobiographical memories that come to mind with no preceding retrieval attempt and that are subjectively experienced as being repetitive. Clinically, they are classified as a symptom of posttraumatic stress disorder. The present work is the first to systematically examine recurrent involuntary memories outside clinical settings. Study 1 examines recurrent involuntary memories among survivors of the tsunami catastrophe in Southeast Asia in 2004. Study 2 examines recurrent involuntary memories in a large general population. Study 3 examines whether the contents of recurrent involuntary memories recorded in a diary study are duplicates of, or differ from, one another. We show that recurrent involuntary memories are not limited to clinical populations or to emotionally negative experiences; that they typically do not come to mind in a fixed and unchangeable form; and that they show the same pattern regarding accessibility as do autobiographical memories in general. We argue that recurrent involuntary memories after traumas and in everyday life can be explained in terms of general and well-established mechanisms of autobiographical memory.     

Reactions to Different Types of Forced Distribution Performance Evaluation Systems

Purpose  We isolate and describe four key elements that distinguish different forms of forced distribution systems (FDS). These key elements are the consequences for low performers, differentiation of rewards for top performers, frequency of feedback, and comparison group size. We examine how these elements influence respondents’ attraction to FDS. Design/methodology/approach  Undergraduate students (n = 163) completed a policy capturing study designed to determine how these four FDS elements influence their attraction to FDS. We examine the relative importance of these elements that most influence attraction to different FDS, as well as individual attributes (i.e., cognitive ability, gender, and major) that may affect those preferences. Findings  Respondents were most attracted to systems with less stringent treatment of low performers, high differentiation of rewards, frequent feedback and large comparison groups. Consequences for low performers were nearly twice as influential as any other element. Respondents with higher cognitive ability favored high reward differentiation and males were less affected by stringent consequences for low performers. Implications  Before practitioners implement FDS, it would be prudent to consider all four elements examined in this study—with the treatment of low performers being the most salient issue. Future accounts of FDS should clarify the nature of these elements when reporting on FDS. Such precision will be useful in generating a knowledge base on FDS. Originality/value   We add precision to the discussion of FDS by identifying four key elements. This is one of the first studies to examine perceptions of FDS from a ratee perspective.

The disutility of the hard-easy effect in choice confidence

A common finding in confidence research is the hard-easy effect, in which judges exhibit greater overconfidence for more difficult sets of questions. Many explanations have been advanced for the hard-easy effect, including systematic cognitive mechanisms, experimenter bias, random error, and statistical artifact. In this article, I mathematically derive necessary and sufficient conditions for observing a hard-easy effect, and I relate these conditions to previous explanations for the effect. I conclude that all types of judges exhibit the hard-easy effect in almost all realistic situations. Thus, the effect’s presence cannot be used to distinguish between judges or to draw support for specific models of confidence elicitation.     

The abstract selection task: new data and an almost comprehensive model

A complete quantitative account of P. Wason's (1966) abstract selection task is proposed. The account takes the form of a mathematical model. It is assumed that some response patterns are caused by inferential reasoning, whereas other responses reflect cognitive processes that affect each card selection separately and independently of other card selections. The model parameters assess the contributions of different interpretational, inferential, and heuristic factors that jointly determine performance in the selection task. The interpretation of most of the model parameters in terms of these different factors is validated experimentally. This model of the selection task is the first to account for the observed frequencies of all 16 possible response patterns that can arise.     

Why do people perceive ingroup homogeneity on ingroup traits and outgroup homogeneity on outgroup traits?

People tend to perceive ingroup homogeneity on ingroup stereotypical traits and outgroup homogeneity on outgroup stereotypical traits (e.g., Kelly, 1989; Simon, 1992a; Simon & Pettigrew, 1990). If it is assumed that people use homogeneity ratings to indicate the extent to which groups possess traits, then this stereotype effect may be interpreted as an expression of perceived trait possession (i.e., ingroups possess ingroup stereotypical traits and outgroups possess outgroup stereotypical traits). If it is further assumed that research participants abide by the conversational norm of appropriate quantity (e.g., Bless, Strack, & Schwarz, 1993), then this stereotype effect should be significantly reduced following prior expressions of perceived trait possession. A literature review and two minimal group experiments (Ns = 75, 104) supported this prediction. This evidence is discussed in relation to the outgroup homogeneity effect and self-categorization theory.     

Reviews: Books

ZEN MASTERS: A MAVERICK, A MASTER OF MASTERS, AND A WANDERING POET. By John Stevens, 161 pp. Kodansha International: Tokyo/NY/London, 1999. $13.00. THE DEVELOPING MIND: TOWARD A NEUROBIOLOGY OF INTERPERSONAL EXPERIENCE. By Daniel J. Siegel. 394 pp. New York: The Guilford Press, 1999. $37.95. JESUS: A PSYCHOLOGICAL BIOGRAPHY. By Donald Capps. 288 pp. St. Louis: Chalice Press, 2000. $29.99.