Injury increases the risk for PTSD: an examination of potential neurobiological and psychological mediators

A growing number of common traumatic events involve both physical and emotional injuries. In contrast to previously held beliefs, the rapidly growing body of literature shows quite convincingly that physical injury, over and above exposure to the traumatic event itself, increases rather than decreases the risk for posttraumatic stress disorder (PTSD). A pertinent question becomes how bodily injury contributes to the risk of developing PTSD. In this article, we review contemporary findings regarding the neurobiological and psychological mechanisms by which bodily injury may augment or independently contribute to chronic posttraumatic stress. In addition, we propose three theoretical pathways through which physical injury can increase the risk for PTSD. These pathways are: additive, unique, and recovery impeding. Finally, we highlight unresolved issues pertaining to each one of these pathways and propose directions for future research to address them.     

Spontaneous classification in action by a human-enculturated and language-reared bonobo (Pan paniscus) and common chimpanzees (Pan troglodytes).

The authors investigated the formal features of spontaneous manipulations used by 1 bonobo (Pan paniscus) and 2 common chimpanzees (Pan troglodytes) to classify objects in action. Chimpanzees' manipulations were evenly split between serial, one-at-a-time acts on 1 object and parallel, two-at-a-time acts on 2 or 3 objects. Chimpanzees systematically combined their manipulations into routines to generate class-consistent categories of objects. Their routines featured much reproduction of the same manipulations, planful acts that anticipated follow-up manipulations, and manipulations that were reciprocal to each other to accomplish an end. In all these respects, chimpanzees' manipulations were similar to those of 2-year-old human infants. In others they differed. Chimpanzees' routines were mainly based on a linear integration of manipulations. Classifying in action was only infrequently produced by hierarchically integrated routines.     

Spontaneous logicomathematical constructions by chimpanzees (Pan troglodytes, P. paniscus)

Two experiments investigated the spontaneous construction of precursory logicomathematical operations by human-enculturated and language-reared chimpanzees (Pan troglodytes, Pan paniscus) when they were interacting freely with objects. In experiment 1, three chimpanzees ranging in age from 6 to 18 years were presented with sets of six objects. Chimpanzees constructed equivalence, order and reversibility relations within single sets of objects as well as between two or three contemporaneous sets of objects. The chimpanzees’ logicomathematical operations were more advanced, including infrequent and minimal operations on three sets, than those of some previously investigated younger nonenculturated common chimpanzees. In experiment 2, six chimpanzees ranging in age from 6 to 21 years were presented with sets of 12 objects. Chimpanzees constructed more advanced operations on single sets, but not on contemporaneous sets. The results suggest partial convergence and partial divergence between development of logicomathematical cognition in chimpanzees and humans. Received: 20 January 1999 / Accepted after revision: 9 August 1999     

Spontaneous class grouping behavior by bonobos (Pan paniscus) and common chimpanzees (P. troglodytes)

Two experiments investigated spontaneous class grouping behavior by human-enculturated and language-reared bonobos (Pan paniscus) and common chimpanzees (P. troglodytes). In experiment 1, three chimpanzees ranging in age from 6 to 18 years were presented with six objects. The objects embodied three conditions: additive, multiplicative and disjoint classes. All chimpanzees spontaneously produced single- and two-category classifying. In experiment 2, six chimpanzees ranging in age from 6 to 21 years were presented with 12 objects in the same class conditions. Chimpanzees mainly produced single-category classifying. Their two-category classifying was more rudimentary than that found in experiment 1. Chimpanzees did not produce any three-category classifying which would be necessary to construct the hierarchies that humans begin to construct during early childhood. Received: 1 February 1999 / Accepted after revision: 9 August 1999     

Post-divorce adaptation and the attribution of responsibility

A study was conducted to explore the possible relationship between post-divorce adjustment and the attributions divorced women give for the failure of their marriages. The study revealed that significantly more subjects who attributed their divorces to interactive rather than personal factors were more active, more socially skilled, happier, more optimistic, and less likely to blame themselves rather than outside forces for failures. The findings were also analyzed in light of whether or not subjects had initiated their divorce proceedings. The importance of making interactive attributions was discussed.We would like to thank Cynthia Weinman for her help in conducting the study. We are also grateful to the City University of New York for providing the funds for this research.