Causality and Contingency: Some Conceptual Considerations

The Psychological Record - The logical features of causality (necessary connection, succession, and contiguity) are examined in regard to respondent and operant behaviors. It is emphasized that...     

From the Flos Substantiae to the Vortex: A Shift in Leibniz's Early Philosophy

In February 1676, one of Leibniz's main concerns is with the problem of the seat of the soul and its relationship with the body, to which, in two very short papers, he provides two different solutions: the doctrine of the flos substantiae and the vortex theory. By analyzing the former, I suggest that, despite what other scholars claim, it is far from being an earlier exposition of the notion of monad. I argue that this doctrine is entertained by Leibniz only for a period, but is rejected later on and excluded from the final monadic system. This hypothesis seems to be supported by the shift to the notion of a vortex, which – despite having some evident pantheistic and monistic implications – offers a different solution to the problem of mind‐body union, by identifying the soul as the only cement of matter. In this article, by following the progress of such a shift, we discover some fascinating nuances in the young Leibniz's development.     

Estimating Age-Based Developmental Trajectories Using Latent Change Score Models Based on Measurement Occasion

Abstract

Accelerated longitudinal designs (ALDs) are designs in which participants from different cohorts provide repeated measures covering a fraction of the time range of the study. ALDs allow researchers to study developmental processes spanning long periods within a relatively shorter time framework. The common trajectory is studied by aggregating the information provided by the different cohorts. Latent change score (LCS) models provide a powerful analytical framework to analyze data from ALDs. With developmental data, LCS models can be specified using measurement occasion as the time metric. This provides a number of benefits, but has an important limitation: It makes it not possible to characterize the longitudinal changes as a function of a developmental process such as age or biological maturation. To overcome this limitation, we propose an extension of an occasion-based LCS model that includes age differences at the first measurement occasion. We conducted a Monte Carlo study and compared the results of including different transformations of the age variable. Our results indicate that some of the proposed transformations resulted in accurate expectations for the studied process across all the ages in the study, and excellent model fit. We discuss these results and provide the R code for our analysis.