Dichromatic Colour Vision in Wallabies as Characterised by Three Behavioural Paradigms

Despite lacking genetic evidence of a third cone opsin in the retina of any Australian marsupial, most species tested so far appear to be trichromatic. In the light of this, we have re-examined colour vision of the tammar wallaby which had previously been identified as a dichromat. Three different psychophysical tests, based on an operant conditioning paradigm, were used to confirm that colour perception in the wallaby can be predicted and conclusively explained by the existence of only two cone types. Firstly, colour-mixing experiments revealed a Confusion Point between the three primary colours of a LCD monitor that can be predicted by the cone excitation ratio of the short- and middle-wavelength sensitive cones. Secondly, the wavelength discrimination ability in the wallaby, when tested with monochromatic stimuli, was found to be limited to a narrow range between 440 nm and 500 nm. Lastly, an experiment designed to test the wallaby’s ability to discriminate monochromatic lights from a white light provided clear evidence for a Neutral Point around 485 nm where discrimination consistently failed. Relative colour discrimination seemed clearly preferred but it was possible to train a wallaby to perform absolute colour discriminations. The results confirm the tammar wallaby as a dichromat, and so far the only behaviourally confirmed dichromat among the Australian marsupials

Stability and change in personality and personality disorders

In this paper, we review recent findings related to stability and change in personality and personality disorder. Estimates of stability vary depending on a number of methodological and substantive factors. These factors include the type of stability being examined, the type of construct being assessed, the method being used to assess personality, how participants are sampled, and developmental trends in personality stability and change. We describe current evidence about personality stability with respect to each of these factors. We conclude that current gaps in the literature can be filled by more carefully attending to factors that impact estimates of stability and change, and provide recommendations about how future research can fill those gaps

A motivational framework of personality development in late adulthood

Meta-analytic evidence shows that most personality traits tend to increase through early adulthood and middle age but decrease in late adulthood, whereas Emotional Stability continues to increase throughout late adulthood. We propose that these normative patterns of personality development can be explained by motivational theories of aging. Specifically, decreases in Extraversion, Agreeableness, Conscientiousness, and Openness to Experience may reflect a reduced capacity to control one's environment, whereas continued increases in Emotional Stability reflect increases in individual's ability to compensate and cope with age-graded losses. Pairing motivational theories of aging with longitudinal evidence in personality science provides an explanation for empirical patterns of personality trait development and raises interesting possibilities to promote healthy aging

Assessing Personality Change: Introduction to the Special Section

Both clinical and personality psychologists are interested in assessing personality change, although they have tended to approach the issue in different ways. In this paper we argue that both sub-fields should focus more on basic issues in the assessment of personality change, and that they would make more progress on this issue together than alone. This Special Section on the Assessment of Personality Change includes four papers by researchers working primarily in basic personality science. Each paper addresses specific ways to advance the assessment of personality change that have both basic and applied clinical relevance, but collectively they show how far the field still has to go

Personality and Compassion for Animals

People vary in their compassion for animals, likely due in part to more variation in more basic personality and interpersonal behavior attributes. Previous research has generally suggested that more communal and agreeable people also tend to be more compassionate to animals. However, this research is limited regarding the range and depth of individual differences used to examine this issue. The goal of this preregistered study was to extend previous research by examining associations between compassion for animals and a wider range of variables than has been previously examined. In a representative sample of American adults (n = 992), we tested associations between compassion for animals and (a) Big Five personality trait domains, (b) Big Five trait aspects, (c) maladaptive Big Five trait domains, (d) interpersonal values, and (e) interpersonal problems. Results supported our hypothesis that compassion for animals is related to communion/agreeableness and openness to experience. Consistent with our hypotheses, the compassionate aspect of agreeableness drove correlations with that trait. Contrary to our hypotheses, maladaptive antagonism was not more strongly related to compassion for animals than normal-range agreeableness. The results provide a fuller portrait of the personological foundation of compassion for animals. Specifically, people who are more communal/agreeable and open tend to be more compassionate toward animals. This suggests that personality-related patterns of behavior among humans extend to human-animal interactions. Results also provide a basis for future work examining the mechanisms underlying human compassion for animals

Kerr non-linearity in a superconducting Josephson metamaterial

We present a detailed experimental and theoretical analysis of the dispersion and non-linear Kerr frequency shifts of plasma modes in a one-dimensional Josephson junction chain containing 500 SQUIDs in the regime of weak nonlinearity. The measured low-power dispersion curve agrees perfectly with the theoretical model if we take into account the Kerr renormalisation of the bare frequencies and the long-range nature of the island charge screening by a remote ground plane. We measured the self- and cross-Kerr shifts for the frequencies of the eight lowest modes in the chain. We compare the measured Kerr coefficients with theory and find good agreement

Kerr coefficients of plasma resonances in Josephson junction chains

We present an experimental and theoretical analysis of the self- and cross-Kerr effect of extended plasma resonances in Josephson junction chains. We calculate the Kerr coefficients by deriving and diagonalizing the Hamiltonian of a linear circuit model for the chain and then adding the Josephson non-linearity as a perturbation. The calculated Kerr-coefficients are compared with the measurement data of a chain of 200 junctions. The Kerr effect manifests itself as a frequency shift that depends linearly on the number of photons in a resonant mode. By changing the input power on a low signal level, we are able to measure this shift. The photon number is calibrated using the self-Kerr shift calculated from the sample parameters. We then compare the measured cross-Kerr shift with the theoretical prediction, using the calibrated photon number.Comment: 10 pages, 9 figure

Health, environmental, and animal rights motives for vegetarian eating.

Health, the environment, and animal rights represent the three main reasons people cite for vegetarian diet in Western societies. However, it has not been shown that these motives can be distinguished empirically, and little is known about what kind of people are likely to be compelled by these different motives. This study had three goals. First, we aimed to use construct validation to test whether develop health, environmental, and animal rights motives for a vegetarian diet could be distinguished. Second, we evaluated whether these motivations were associated with different demographic, behavioral, and personality profiles in three diverse samples. Third, we examined whether peoples' motivations were related to responses to vegetarian advocacy materials. We created the Vegetarian Eating Motives Inventory, a 15-item measure whose structure was invariant across three samples (N = 1006, 1004, 5478) and two languages (English and Dutch). Using this measure, we found that health was the most common motive for non-vegetarians to consider vegetarian diets and it had the broadest array of correlates, which primarily involved communal and agentic values. Correlates of environmental and animal rights motives were limited, but these motives were strong and specific predictors of advocacy materials in a fourth sample (N = 739). These results provide researchers with a useful tool for identifying vegetarian motives among both vegetarian and non-vegetarian respondents, offer useful insights into the nomological net of vegetarian motivations, and provide advocates with guidance about how to best target campaigns promoting a vegetarian diet

Charting self‐esteem during marital dissolution

Objective: The purpose of this study was to chart changes in self-esteem before and after marital dissolution to identify the factors that shape individuals' self-esteem during this life transition. Method: We analyzed 10 annual waves of self-esteem data from 291 divorcees from a nationally representative panel study of the Netherlands (N ~ 13,000). We charted the course of self-esteem before and after marital dissolution and tested a broad set of moderator variables that may shape individuals' self-esteem trajectories. Results: The average divorcee experienced significant decrease in self-esteem preceding marital dissolution and remained stable afterward. There were substantial individual differences in self-esteem trajectories, both before and after marital separation. Divorcees who experienced financial hardship, were affiliated with a church or religion, or scored low in Conscientiousness showed the most pronounced decrease in self-esteem during the years approaching marital dissolution. Conclusion: This study highlights the importance of assessing people multiple times before and after marital dissolution to dissect how people approach and respond to this life event. Results are consistent with perspectives that view divorce as an opportunity to abate the strains of an unhappy marriage

Charting self-esteem during marital dissolution.

ObjectiveThe purpose of this study was to chart changes in self-esteem before and after marital dissolution to identify the factors that shape individuals' self-esteem during this life transition.MethodWe analyzed 10 annual waves of self-esteem data from 291 divorcees from a nationally representative panel study of the Netherlands (N ~ 13,000). We charted the course of self-esteem before and after marital dissolution and tested a broad set of moderator variables that may shape individuals' self-esteem trajectories.ResultsThe average divorcee experienced significant decrease in self-esteem preceding marital dissolution and remained stable afterward. There were substantial individual differences in self-esteem trajectories, both before and after marital separation. Divorcees who experienced financial hardship, were affiliated with a church or religion, or scored low in Conscientiousness showed the most pronounced decrease in self-esteem during the years approaching marital dissolution.ConclusionThis study highlights the importance of assessing people multiple times before and after marital dissolution to dissect how people approach and respond to this life event. Results are consistent with perspectives that view divorce as an opportunity to abate the strains of an unhappy marriage