Taking personality selection bias seriously in animal cognition research: a case study in capuchin monkeys (Sapajus apella)

In most experimental work on animal cognition, researchers attempt to control for multiple interacting variables by training subjects prior to testing, allowing subjects to participate voluntarily, and providing subjects with food rewards. However, do such methods encourage selection bias from subjects’ personalities? In this study, we trained eighteen zoo-housed capuchin monkeys (Sapajus apella) for two experiments, under conditions of positive reinforcement (i.e. food rewards) and free-choice participation. Using a combination of behavioral and rater-based methods, we identified and validated five personality dimensions in these capuchins (Assertiveness, Openness, Neuroticism, Sociability, and Attentiveness). Scores on Openness were positively related to individual differences in monkey task participation, reflecting previous work showing that such individuals are often more active, curious, and willing to engage in testing. We also found a negative relationship between scores on Assertiveness and performance on tasks, which may reflect the trade-offs between speed and accuracy in these animals’ decision-making. Highly Assertive individuals (the most sociable within monkey groups) may also prioritize social interactions over engaging in research. Lastly, monkeys that consistently participated and performed well on both tasks showed significantly higher Openness and lower Assertiveness compared to others, mirroring relationships found between personality, participation, and performance among all participants. Participation and performance during training was clearly biased toward individuals with particular personalities (i.e. high Openness, low Assertiveness). Results are discussed in light of the need for careful interpretation of comparative data on animal cognition and the need for researchers to take personality selection bias more seriously.     

Use of gesture sequences in captive chimpanzee (Pan troglodytes) play

This study examined the use of sensory modalities relative to a partner’s behavior in gesture sequences during captive chimpanzee play at the Chimpanzee and Human Communication Institute. We hypothesized that chimpanzees would use visual gestures toward attentive recipients and auditory/tactile gestures toward inattentive recipients. We also hypothesized that gesture sequences would be more prevalent toward unresponsive rather than responsive recipients. The chimpanzees used significantly more auditory/tactile rather than visual gestures first in sequences with both attentive and inattentive recipients. They rarely used visual gestures toward inattentive recipients. Auditory/tactile gestures were effective with and used with both attentive and inattentive recipients. Recipients responded significantly more to single gestures than to first gestures in sequences. Sequences often indicated that recipients did not respond to initial gestures, whereas effective single gestures made more gestures unnecessary. The chimpanzees thus gestured appropriately relative to a recipient’s behavior and modified their interactions according to contextual social cues.     

The simple man: The consumption behavior of the principled life

In this study, we analyze the Simple Man, a label for those men who have above-average means in education, household income, or net worth but who consume inconspicuously and modestly below their means. We interviewed 27 men in the Northwest, Midwest, Southeast and Northeast regions of the United States and found that these men have highly individualistic identities and backgrounds yet appear to stray from products that separate them from others. These men also seem to have reached a level of contentment, not needing products or material possessions to achieve fulfillment, status, or a particular masculine identity. These men have practical and durable tastes that reflect low cultural capital (LCC) consumption but have the means and education in many instances to engage in high cultural capital (HCC) consumption. The men in this study adamantly proclaim that they do not define themselves by what they own nor do they appear to define themselves primarily by what they do, at least in terms of occupation. In short, these men appear complex in many ways yet live simple lives, or what might be termed complex simplicity. Copyright © 2013 John Wiley & Sons, Ltd.     

The HEXACO–60: A Short Measure of the Major Dimensions of Personality

According to Jung anima and animus are functions, themselves largely unconscious, mediating between the ego and the deeper unconscious. Their manifestations in projection (also in dream, myth, etc.) are called the soul image. The soul image and the functions which it represents usually have sexual characteristics contrary to those of the conscious personality and are compensatory and complementary thereto.

Kinaesthetic responses in the Rorschach test are generally regarded as carriers of projections from the unconscious. Therefore, when personality imbalance and increased liability to projection occur as in neurosis, the proportion of contrasexual Ms should be larger in neurotic than in normal groups. Using four groups containing each 100 adult subjects: healthy women, neurotic women, healthy men and neurotic men, the hypothesis was tested and confirmed, affording some confirmation to Jungian theory.     

Measuring Individual Differences in Trait Sympathy: Instrument Construction and Validation

In 3 studies, I report on the construction and validation of a multifaceted, self-report measure of an individual's tendency to experience feelings of sorrow or concern for the suffering of others. The Trait Sympathy Scales (TSS) displayed solid properties of reliability (Studies 1–3), content validity (Study 1), factorial validity (Study 1), construct-related validity (Studies 1–3), convergent and discriminant validity (Study 2), as well as predictive validity (Study 3). Findings support the TSS as a sound instrument that offers several advantages over Davis's (1980) Empathic Concern subscale.     

Sudden gains as a long-term predictor of treatment improvement among children in community mental health organizations

ObjectiveSudden gains have been described as rapid, sizeable changes observed between treatment sessions and have been associated with improved treatment outcome in adults. The current study examined weekly sudden gains among children seeking treatment in the community mental health setting.MethodParticipants were 161 children (age M = 10.58, SD = 1.73; 69.6% male; 47.8% Caucasian) and their parents who were randomized to one of three treatment modalities and were administered weekly and quarterly assessments throughout treatment.ResultsWhen idiographic (youth- and parent-identified “top problems”) and nomothetic measures (standardized checklists) were used to calculate sudden gains (i.e., gain must be large: in absolute terms, relative to prior session, and relative to changes in prior and subsequent sessions), 20–42% of participants experienced at least one sudden gain during treatment. Most sudden gains occurred early in treatment, and session content of relaxation was associated with sudden gain presence. Using a modified Bonferonni correction, sudden gains predicted overall symptom levels at final assessment (i.e., last assessment obtained following post-treatment) even after controlling for pre-treatment symptom levels and magnitude of the overall gain from pre- to post-treatment.ConclusionsSuddenness of gains may have a direct effect on long-term treatment outcome among children in the community.     

Perceptions of success and life satisfaction: a gender examination in Taiwan

Gender socialization creates an expectation that men should achieve success (regardless of how it is defined), so men are under greater pressure than women when encountering successful persons and, accordingly, experience lower life satisfaction. Two experiments were conducted in Taiwan to test the proposed effects on life satisfaction. Study 1 showed that 149 students were more likely to infer successful targets as male than female. A path model demonstrated that feeling less powerful against ideal same‐sex persons predicted men's (but not women's) lower life satisfaction after they read about successful targets. Study 2 (106 students) showed that reading about successful targets had differential effects for men and women. Implications regarding culture, gender, and life satisfaction were discussed.     

Brain Potentials from Normal Speakers and Stutterers

The purposes of this study were to determine the differences in self-esteeem and alienation between homosexual and heterosexual American males, and the differences in self-esteem and alienation in homosexual males, by selected demographic variables and sexual behavior. Eighty-six American male homosexuals indicated significantly greater alienation than heterosexual males, but similar self-esteem levels. Religion, oral-genital insertion preference, and marital status were significantly related to self-esteem and alienation, whereas anal intercourse insertion preference and degree of homosexuality were not found to be significantly related to self-esteem and alienation.     

Mechanisms of change in adolescent life satisfaction: A longitudinal analysis

This study explored the psychosocial mechanisms of change associated with differences in levels and linear change of adolescents' global life satisfaction across a 2-year time period. Based on a theoretical model proposed by Evans (1994), this study tested the relations between selected personality (i.e., extraversion and neuroticism) and environmental (stressful life events) variables and global life satisfaction when mediated by internalizing and externalizing problems. The results suggested support for internalizing problems as a mediator of the relationship of personality and environmental variables with life satisfaction. Pathways mediated by internalizing problems significantly predicted levels and linear change of life satisfaction across a 2-year time span. Furthermore, pathways mediated by externalizing problems significantly predicted the level but not the linear change of life satisfaction. Thus, behavior problems and their antecedents appear to relate significantly to adolescents' perceptions of their quality of life. Implications for adolescent mental health promotion were discussed.