The effects of intrinsic and extrinsic rewards in a risk-taking situation

This study varied both the intrinsic and extrinsic rewards associated with performing a task in a risk taking situation. When the task performed to win a prize provided little if any intrinsic reward, subjects liked and tried for prizes that were easy to obtain. In contrast, when the task was intrinsically rewarding, subjects liked and tried for those prizes that were somewhat more difficult to obtain. In addition, subjects were more likely to like and try for prizes easier to obtain when the extrinsic reward was high.     

Sport participation among adolescent girls: Role conflict or multiple roles?

This study explored selected roles as criteria for social status among high school females with particular reference to participation in interscholastic athletics. Six hundred and twenty-seven female high school students completed the School Climate Questionnaire and, using a 5-point Likert scale, rated different role/activity choices. There were significant differences between participants and nonparticipants with respect to roles selected for future status; however, no significant relationship was found between groups and their identification of the criteria for peer approval. Overall, high school females exhibited multidimensional self-identities that differed in relation to their involvement in sports and the social groups used as their point of reference.     

Questions of times: Conflicting time scales in historical perspective

The idea of ``Jewish' time highlights many problems related to the conflict between Judaism and Christianity. This paper focuses on two points: the reckoning of the Jewish era and the interpretation of the notion of time in the Bible. Jewish time pulsates to a rhythm of temporal markers which also divide it into secular and religious time. This division, however, this dual register of temporality, also enables Jews to alternate a ``Jewish' register with a ``universal' one. Traditional Jewish sources indicate that the principle of determining the date by calculating from the creation of the world (anno mundi) appeared during the period of the Second Temple. The question of elapsed time, deduced from different readings of the Biblical text, launched Jews and Christians on parallel lines of time. The history of the genesis of the notion of time asserts that the circular representation of temporality, sometimes called indigenous to ancient societies, was replaced by a representation that was vertical, then linear. These stages served as a scale for measuring the progress and evolution of societies. The Christian notion was supposed to characterize European time as an ``infinite line' along which events are placed, in contrast to Israelite time, identifiable through its contents, and in which time is ``full' and concrete, with no room for (re)ordering or arranging its episodes. This revised version was published online in August 2006 with corrections to the Cover Date.     

Nicotine and familial vulnerability to schizophrenia: a discordant twin study

Tobacco use is significantly associated with schizophrenia. However, it is not clear if smoking is associated with the illness itself, treatment, or underlying vulnerability to the disease. Smoking was studied in a sample of schizophrenic probands (n = 24), their unaffected co-twins (n = 24), and controls (n = 3,347). Unaffected co-twins had higher rates of daily smoking than controls. Probands and co-twins were more frequently unsuccessful in attempts to quit than controls. Probands reported shaky hands and depression following smoking cessation more often than controls, whereas unaffected co-twins reported difficulty concentrating, drowsiness, nervousness, and headache following smoking cessation more often than controls. Results are consistent with the hypothesis that nicotine use is influenced by familial vulnerability to schizophrenia, not just clinical schizophrenia per se.