The real and the ideal; gender differences in heterosexual behaviour among Norwegian adolescents

This article focuses on gender differences in early heterosexual behaviour among Norwegian adolescents. The material comprised a random sample of 3000 Norwegian adolescents aged 17–19 years. The response rate was 63%. Data were collected by means of anonymous self-administered questionnaires. Sixty-nine per cent of the girls and 59% of the boys had had sexual intercourse. The majority of the adolescents, and a larger percentage of girls than of boys, had their first intercourse within a relationship of mutual commitment. The boys' first coital partners were 0.2 years younger than the boys themselves and the girls' partners were 2.8 years older than were the girls. Boys had had more coital partners than girls but girls had had intercourse more often than boys. Coital frequency was affected more by how long the adolescents had known the partner than by gender as such. In conclusion, boys and girls aged between 17 and 19 years form part of couples at two different stages of development. For this reason, boys and girls accumulate different sexual experiences in the early stage of their sexual careers.     

Developmental sequences in the age of onset of disruptive child behaviors

Retrospective and prospective reports of the onset of disruptive child behaviors were analyzed in a sample of clinic-referred boys. The younger boys (ages 7–9 years), compared with the older boys (ages 10–12 years), showed the highest level of disruptive behavior and, judging from mothers' reports, had the fastest progression of onsets from less serious to more serious problem behaviors. Despite some overlap, developmental sequences in problem behavior within the domains of hyperactivity/inattention, oppositional behavior, and conduct problems were similar across the two age groups. This was also the case for developmental sequences of overt or confrontive problem behaviors and covert or concealing conduct problems. Sequences of the onset of oppositional behavior and conduct problems were validated through prospective data, based on the information from mothers, teachers, and boys themselves. The implications of the findings are discussed for the formulation of developmental pathways of behavior and the analysis of causal factors.     

A flavor paired with lithium chloride blocks the formation of a pentobarbital-lithium chloride association

Thirsty rats were used in order to determine whether a vinegar solution, which had been paired with an injection of lithium chloride, could block the formation of an association between a pentobarbital- and a lithium chloride-induced state. During phase 1 the rats in the blocking group had a 2.0% vinegar solution paired with an injection of 240 mg/kg of lithium chloride, during phase 2 these rats were reexposed to the vinegar prior to each injection of 20 mg/kg of pentobarbital and 240 mg/kg of lithium chloride, and during phase 3 these rats were given access to a novel 0.75% saccharin solution and were injected with pentobarbital after saccharin removal. Animals with this history did not form an association between the pentobarbital- and lithium chloride-induced states during phase 2 as evidenced by their refusal to consume the saccharin solution over repeated pairings of saccharin with pentobarbital during phase 3. Control groups that received forward pairings of pentobarbital and lithium chloride, in the absence of a previously conditioned vinegar solution during phase 2, formed an association between pentobarbital and lithium chloride. These findings indicate that drug states and flavors can interfere with each others' capacity to predict the occurrence of lithium chloride.     

Psychological conceptions of randomness

This article presents a critique of the concept of randomness as it occurs in the psychological literature. The first section of our article outlines the significance of a concept of randomness to the process of induction; we need to distinguish random and non-random events in order to perceive lawful regularities and formulate theories concerning events in the world. Next we evaluate the psychological research that has suggested that human concepts of randomness are not normative. We argue that, because the tasks set to experimental subjects are logically problematic, observed biases may be an artifact of the experimental situation and that even if such biases do generalise they may not have pejorative implications for induction in the real world. Thirdly we investigate the statistical methodology utilised in tests for randomness and find it riddled with paradox. In a fourth section we find various branches of scientific endeavour that are stymied by the problems posed by randomness. Finally we briefly mention the social significance of randomness and conclude by arguing that such a fundamental concept merits and requires more serious considerations.     

HyperCard administration of a block-design task

HyperCard (Atkinson, 1987) is a new development environment for the Macintosh that shows promise for use in psychological research and testing. In this paper, we discuss the development of HyperCard stackware with which a block-design task similar to that of the Wechsler Adult Intelligence Scale-Revised (WAIS-R) can be administered. The reliability and validity of the computerized block-design task was evaluated by administering both the computerized task and the WAIS-R subtest to college undergraduates. Results indicated that the computerized task’s reliability compared favorably with that of the WAIS-R subtest. Validity coefficients were equivocal; although an elapsed-time measure showed moderate correlation between the tasks, the numbers of designs correctly completed in each condition were not significantly correlated.