Exploring sex differences in science enrolment intentions: An application of the General Model of Academic Choice

In many countries there remain substantial sex differences in enrolments in elective science courses, despite concerted efforts in recent years to alleviate them. This paper explores the reasons for these differences by comparing models of male and female enrolment intentions in elective courses in biology, chemistry and physics. The models are based on responses from approximately 450 students from 5 Australian high schools. First, a theoretical model, the Science Enrolment Model, was derived from Eccles and colleagues’ General Model of Academic Choice. Students’ responses were then used to develop empirical models of enrolment intentions in the three elective courses. Analyses for the models were conducted using the LISREL “mean structures” extension. Sex differences in the dependent variables in the models were then attributed to the relevant sets of independent variables. Substantial sex differences were identified in measures of perceived career value, interest and performance expectations in all three models which explained between 70% and 82% of the sex differences in enrolment intentions.     

Object recognition through eavesdropping: Passive echolocation in bottlenose dolphins

A bottlenose dolphin (Tursiops truncatus) demonstrated the ability to select the matching object in a matching-to-sample task after listening to another dolphin inspect the sample object via echolocation. The listener was prevented from inspecting the sample himself. In Experiment 1, with objects familiar to both dolphins, the listener’s performance was significantly better than chance. In Experiment 2, objects familiar to only one of the dolphins were used. On these trials, the listener’s performance was significantly better than chance only when the inspecting dolphin made a correct choice. Analysis of the listener’s responses when the inspector made an error demonstrated that this contingency was not due to the listener’s matching the inspector’s response, but was apparently due instead to inadequate information in the echo. The results suggest that the listener was able to “eavesdrop” on echoes produced by the inspector’s clicks and derive characteristics of the sample object.     

Examining the Etiology of Reading Disability as Conceptualized by the Hybrid Model

A fairly recent definition of reading disability (RD) is that in the form of a hybrid model. The model views RD as a latent construct that is manifested through various observable unexpected impairments in reading-related skills and through inadequate response to intervention. The current report evaluated this new conceptualization of RD from an etiological perspective. The sample consisted of 2,737 twin pairs in 1st through 4th grade (M_age = 8.52) from the Florida Twin Project on Reading. Using twin analyses, results showed that a substantial proportion of genetic variance, a small proportion of shared environmental, and a small proportion of nonshared environmental variance was attributed to the RD factor. Findings suggest that the etiological architecture of RD closely mirrors the structure of the hybrid model of RD.     

On the importance of motivation in Munchausen by Proxy: the case of Kathy Bush

The recent trial and conviction of Kathy Bush for abusing her daughter is used to illustrate (1) the nature of the motivation, in at least some cases of MBP, and (2) the importance of distinguishing the motivation found in MBP from that found in other forms of child abuse and other conditions involving factitious illness production.