Interplay Between Environmental and Genetic Factors in Temperament/Personality Traits in Horses (Equus caballus).

The aim of the present study was to broach the question of the relative influence of different genetic and environmental factors on different temperament/personality traits of horses (Equus caballus). The researchers submitted 702 horses to standardized experimental tests and investigated 9 factors, either genetic or environmental. Genetic factors, such as sire or breed, seemed to influence more neophobic reactions, whereas environmental factors, such as the type of work, seemed to play a more dominant role in reactions to social separation or learning abilities. Additive effects were evident, showing how environmental factors may modulate behavioral traits. This study constitutes a first step toward understanding the relative weights of genetic factors and how the environment may intervene in determining individual behavioral characteristics. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Personality traits change in adulthood: Reply to Costa and McCrae (2006).

In a response to comments by P. T. Costa, Jr., and R. R. McCrae (see record 2006-00818-002) on the current authors' original article (see record 2006-00818-001), the authors show that Costa and McCrae's writings on personality suggest a belief in immutability of personality traits. The authors agree with Costa and McCrae that new personality trait models that provide an accurate lower order structure of personality traits are needed and explain why the Revised NEO Personality Inventory is not the correct model for that purpose. The authors provide direct evidence refuting the hypothesis that personality traits change only because of biologically based intrinsic maturation. The authors present arguments supporting the contention that meta-analyses should be preferred to single longitudinal studies when drawing inferences about general patterns of personality development. Finally, the authors point out why the differences between their position and Costa and McCrae's are important. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cytochrome Oxidase Activity in the Preoptic Area Correlates With Differences in Sexual Behavior of Intact and Castrated Male Leopard Geckos (Eublepharis macularius).

Although the utility of analyzing behavioral experience effects on neural cytochrome oxidase (CO) activity is well recognized, the behavioral correlates of endogenous differences in CO activity have rarely been explored. In male leopard geckos (Eublepharis macularius), the incubation temperature experienced during embryogenesis (IncT) and age affect CO activity in the preoptic area (POA), an area that modulates copulatory behavior. In this study, the authors assessed whether differences in POA CO activity correlate with differences in sexual behavior in intact and castrated geckos. Males with IncT- and age-dependent increases in POA CO activity mounted females with shorter latencies while intact and after castration and ejaculated more frequently after castration. The authors discuss the predictive value of CO activity and propose similar parallels in other species. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Personality and personality disorders in the DSM-5: Introduction to the special issue.

In this introduction to the special section on Personality and Personality Disorders in DSM-5, the editors briefly describe the major changes proposed by the Work Group on Personality Disorders for DSM-5. They then introduce and describe the key points in the target articles by the Work Group as well as in the commentaries. The aim of this section is to present an arena for the articulation and discussion of the rationale of the proposed changes and the logic and evidence for these proposed changes. Special attention is paid to points of contention, debate, and controversy with regard to the proposed changes. It is the editors' goal to facilitate an open discussion of these issues in an effort to promote a scientifically based and clinically useful product. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Gorillas (Gorilla gorilla) and Orangutans (Pongo pygmaeus) Encode Relevant Problem Features in a Tool-Using Task.

Two important elements in problem solving are the abilities to encode relevant task features and to combine multiple actions to achieve the goal. The authors investigated these 2 elements in a task in which gorillas (Gorilla gorilla) and orangutans (Pongo pygmaeus) had to use a tool to retrieve an out-of-reach reward. Subjects were able to select tools of an appropriate length to reach the reward even when the position of the reward and tools were not simultaneously visible. When presented with tools that were too short to retrieve the reward, subjects were more likely to refuse to use them than when tools were the appropriate length. Subjects were proficient at using tools in sequence to retrieve the reward. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Differences Between Golden Hamsters (Mesocricetus auratus) and Norway Rats (Rattus norvegicus) in Preference for the Sole Diet That They Are Eating.

D. DiBattista (2002) reported that hamsters but not rats showed reduced preferences for the sole diet they had eaten for 10 days. In the current study, the authors fed Norway rats (Rattus norvegicus) a nutritious diet for either 3 or 10 days, then tested them either immediately or 1 or 3 days later. The authors found that like golden hamsters (Mesocricetus auratus), rats exhibited reduced preferences for a prefed diet but only if tested either immediately or 1 day after prefeeding, not if tested 3 days later (when D. DiBattista tested his hamsters). Rats and hamsters differed in the longevity, not the development, of reduced preferences for a palatable food eaten for several consecutive days. Such a response might aid dietary generalists in constructing balanced diets when no single available food is nutritionally adequate. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Asymmetries in the Hippocampus and Amygdala of Chimpanzees (Pan troglodytes).

Magnetic resonance imaging was used to measure the hippocampal and amygdalar volumes of 60 chimpanzees (Pan troglodytes). An asymmetry quotient (AQ) was then used to calculate the asymmetry for each of the structures. A one-sample t test indicated that there was a population-level right hemisphere asymmetry for the hippocampus. There was no significant population-level asymmetry for the amygdala. An analysis of variance using sex and rearing history as between-group variables showed no significant main effects or interaction effects on the AQ scores; however, males were more strongly lateralized than females. Several of these findings are consistent with results found in the human literature. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Visual Kin Recognition and Family Resemblance in Chimpanzees (Pan troglodytes).

The male-offspring biased visual kin recognition in chimpanzees (Pan troglodytes) reported by L. A. Parr and F. B. M. de Waal (1999) was replicated with human (Homo sapiens) participants and a principal components analysis (PCA) of pixel maps of the chimpanzee face photos. With the same original materials and methods, both humans and the PCA produced the same asymmetry in kin recognition as found with the chimpanzees. The PCA suggested that the asymmetry was a function of differences in the distribution of global characteristics associated with the framing of the faces in the son and daughter test sets. Eliminating potential framing biases, either by cropping the photos tightly to the faces or by rebalancing the recognition foils, eliminated the asymmetry but not human participants' ability to recognize chimpanzee kin. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The Effect of Human Command Phonetic Characteristics on Auditory Cognition in Dogs (Canis familiaris).

Six dogs (Canis familiaris) were trained to sit and come reliably in response to tape-recorded commands. The phonemes within these commands were then changed, and the dogs' behavior in response to these modified commands was recorded. Performance markedly declined in all cases, with the type of alteration affecting response to the modified sit command but not to the modified come command. The results suggest that dogs do not perceive a tape-recorded command as simply a physical sound but that they recognize a relationship between certain sounds. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Personality in free-ranging Hanuman langur (Semnopithecus entellus) males: Subjective ratings and recorded behavior.

The authors obtained behavioral observations and personality ratings for 27 free-ranging Hanuman langur males. Subjects were rated using a questionnaire based on the human Five-Factor Model (FFM). Behavioral observations were taken over 5 months using an ethogram that included 50 behaviors. Principal Component Analysis (PCA) of ratings revealed AgreeablenessR, ConfidenceR, and ExtraversionR components. Each personality dimension was associated with a unique set of observed behaviors. PCA of 36 behavioral indices revealed DominanceB, InvolvementB, and ActivityB components. Bivariate correlations showed that AgreeablenessR was negatively correlated with DominanceB; ConfidenceR was positively correlated with DominanceB and InvolvementB but negatively correlated with ActivityB; and ExtraversionR was positively correlated with ActivityB. Dominance rank was positively correlated with ConfidenceR and DominanceB but negatively correlated with AgreeablenessR and ActivityB. These results highlight the comparability of behavioral coding and personality ratings and suggest that some aspects of personality structure were present in the common ancestor of Old World monkeys. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A personality trait model for the Diagnostic and Statistical Manual of Mental Disorders (DSM): The challenges ahead.

Replies to comments (see record 2010-13810-004), (see record 2010-13810-005), (see record 2010-13810-006), (see record 2010-13810-007) on the original article Personality traits and the classification of mental Disorders: Toward a more complete integration in DSM–5 and an empirical model of psychopathology by Robert F. Krueger and Nicholas R. Eaton (see record 2010-13810-003). We were sincerely flattered to discover that John Gunderson, Michael First, Paul Costa, Robert McCrae, Michael Hallquist, and Paul Pilkonis provided commentaries on our target article. In this brief response, we cannot hope to discuss the myriad points raised by this august group. Such a task would be particularly daunting given the diversity of the commentaries. Indeed, the diversity of the commentaries provides a kind of “metacommentary” on the state of personality and psychopathology research. That is, the intellectual diversity contained in the commentaries underlines the substantial challenges that lie ahead of us, in terms of articulating a model of personality and psychopathology with both scientific validity and clinical applicability. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Recognizing Impossible Object Relations: Intuitions About Support in Chimpanzees (Pan troglodytes).

Using looking-time measures, the authors examined untrained chimpanzees' (Pan troglodytes) ability to distinguish between adequate and inadequate support. In 3 experiments, the chimpanzees' sensitivity to different support relations between 2 objects was assessed. In each experiment, the chimpanzees saw a possible and an impossible test event, presented as digital video clips. Looking times in the 3 experiments suggest that chimpanzees use amount of contact between 2 objects, but not type of contact, to distinguish between adequate and inadequate support relations. These results indicate that chimpanzees have some intuition about support phenomena but their sensitivity to relational object properties may differ from that of human infants (Homo sapiens) in this domain. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Handedness in Chimpanzees (Pan troglodytes) Is Associated With Asymmetries of the Primary Motor Cortex but Not With Homologous Language Areas.

The neurobiology of hand preferences in nonhuman primates is poorly understood. In this study, the authors report the first evidence of an association between hand preference and precentral gyrus-morphology in chimpanzees (Pan troglodytes). Hand preferences did not significantly correlate with other asymmetric brain regions associated with language functions in humans including the planum temporale and frontal operculum. The overall results suggest that homologous regions of the motor cortex control hand preferences in humans and apes and that these functions evolved independently of left-hemisphere specialization for language and speech. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Chimpanzees (Pan troglodytes) Are Predominantly Right-Handed: Replication in Three Populations of Apes.

Population-level right-handedness has historically been considered a hallmark of human evolution. Even though recent studies in chimpanzees (Pan troglodytes) have demonstrated population-level right-handedness for certain behaviors, some have questioned the validity and consistency of these findings by arguing that reported laterality effects are specific to certain colonies of apes and to those chimpanzees reared by humans. The authors report evidence of population-level right-handedness in 3 separate colonies of chimpanzees. Moreover, handedness in the 3 colonies was unrelated to the proportion of subjects that were raised by humans. This is the strongest evidence to date that population-level handedness is evident in chimpanzees and is not an artifact of human rearing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Diagnostic Efficiency of DSM-IV Criteria for Borderline Personality Disorder: An Evaluation in Hispanic Men and Women With Substance Use Disorders.

This study examined diagnostic efficiency of Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM-IV), criteria for borderline personality disorder (BPD). One hundred thirty monolingual Hispanic adults (90 men, 40 women) at an outpatient psychiatric and substance abuse clinic were assessed with the Spanish-Language Version of the Diagnostic Interview for DSM-IV Personality Disorders (C. M. Grilo, L. M. Anez, & T. H. McGlashan, 2003). The BPD diagnosis was determined by the best-estimate method. Diagnostic efficiency indices were calculated for all BPD criteria, for the entire study group, and separately by gender. Overall, the best exclusion criterion was affective instability, whereas suicidality or self-injury was the best inclusion criterion and the best predictor overall. These findings did not differ by gender, are similar to those reported elsewhere in the literature, and have implications for the refinement of diagnostic systems. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Following and Joining the Informed Individual in Semifree-Ranging Tonkean Macaques (Macaca tonkeana).

The authors investigated whether Tonkean macaques (Macaca tonkeana) can distinguish between 2 group mates with different knowledge and improve their foraging performance. The subjects were 8 young individuals belonging to a group raised in a 2-acre park. The authors carried out 192 tests in which subgroups of 3 individuals were released in a food search situation. Two leaders could be informed about 2 different food sites. A naive follower could choose to follow 1 leader or another. The follower could find the correct site when 1 leader was informed about food location. There was no evidence that the follower identified the best leader, however. The less well-informed leader generally joined the other leader, prompting the follower to follow them. The followers' pathways were mainly determined by the interactions of leaders. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Review of Consistency in Social Behavior: The Ontario Symposium (Vol. 2).

Reviews the book, Consistency in Social Behavior: The Ontario Symposium (Vol. 2), edited by Mark P. Zanna, E. Tory Higgins, and C. Peter Herman (1982). The volume has two major foci: the consistency of the individual's behaviour in different situations, and the consistency between people's attitudes and their behaviour. These issues have been classic concerns, respectively, of personality and social psychologists. Once upon a time, we as psychologists naively assumed the existence of both forms of consistency. But in the last two decades our faith has been shaken. For the most part, the participants in the Second Ontario Symposium help to restore our faith. But, in doing so, they provide a more sophisticated, qualified view of consistency. In conclusion, this set of papers is a record of, and a testimonial to, the success of the Second Ontario Symposium on Personality and Social Psychology. It is the present reviewer's hope that this biannual event will be continued in the years ahead. Clearly, the Second Symposium was worth the effort involved! (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Positive Geotaxis in Infant Rats (Rattus norvegicus) : A Natural Behavior and a Historical Correction.

Infant rats (Rattus norvegicus) placed on a shallow incline (2°, 4°, or 8°) oriented and moved downhill within 1 min; that is, they displayed positive geotaxis. Their downhill translocation increased with angle of inclination. A variety of possible behavioral elements (e.g., initial orientation, rotational movements, ambulatory velocities) were eliminated as explanations of the geotaxis. Wall contact was recognized as a determinative event: Pups on the inclines showed no orientation with respect to the geogravitational stimulus before contacting a wall. The event of wall contact, however, evoked reliable downhill orientation and more linear movements. Positive geotaxis was created by pups' orientation against walls and an associated increase in movement velocity. This is a distinct perspective on a behavioral response that replaces a traditionally misinterpreted phenomenon. The authors discuss the ecological validity and historical context of these findings. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Review of Personality: Symposia on topical issues, Vol. 1, Nos. 3 and 4 (pp. 213-388).

Reviews, "Personality: Symposia on topical issues, Vol. 1, Nos. 3 and 4 (pp. 213-388)" (1951). The two volumes provide 11 articles on Hypnosis and Personality and seven articles on Hypnotherapy. The reviewer concludes that, in spite of the question of multiple publication in a time when nearly all outlets for publication are crowded, this symposium is very valuable; it presents some new material, and its summaries and surveys and full bibliographies make it very useful for the student, investigator, and practitioner. (PsycINFO Database Record (c) 2010 APA, all rights reserved)