Targets of attack and defense in play-fighting of the Djungarian hamster Phodopus campbelli: Links to fighting and sex

Analysis of the body targets attacked and defended during play-fighting by juvenile Djungarian hamsters Phodopus campbelli revealed that about 70% of all attacks were directed at the mouth. If successfully contacted, the mouth was briefly licked and nuzzled. The remaining playful attacks were gentle bites directed at the rump, and to a lesser extent, the top of the head. During serious fighting the top of the head and the rump are targets of attack, whereas the mouth is not. Licking and nuzzling the mouth was found to be a behavior performed by adult males at the beginning of sexual encounters. Therefore, play-fighting in juvenile hamsters cannot be thought of merely as a form of “mock fighting” since the principal target is seemingly sexual, not agonistic. The data also show that of the sexual body targets contacted, adult females are more likely to defend the mouth. In this way it is suggested that targets attacked and defended during juvenile play-fighting are derived from adult contexts in which such targets are defended. This hypothesis accounts for the prevalence of agonistic targets in the play-fighting of many species, and may provide a rationale for classifying those amicable targets that are competed for during play-fighting.     

Lack of effects of environmental changes on agonistic behaviour patterns in a stabilizing group of stumptailed macaques (Macaca arctoides)

To evaluate how constant the form of agonistic interactions in the event of environmental changes is, a group of 11 stumptailed macaques, formed shortly before the start of the study, was observed under the following spatial conditions: in 10 and 18 m² cages, and in a 50,000 m² woodland. Results showed that the frequency of agonistic interactions was little affected by spatial density; however, the number of participants involved in aggressive interactions increased in the cage. Formal biting, which presumably acts as a regulator of social tension, was less frequent in the park. Patterning of agonistic interactions was little affected by spatial density. Such “robustness” makes the form of aggression liable to be used as a potentially useful parameter in interspecific comparisons.     

Realism and Empirical Equivalence

Journal of Philosophical Logic - The main purpose of this paper is to investigate various notions of empirical equivalence in relation to the two main arguments for realism in the philosophy of...     

An Accuracy Argument in Favor of Ranking Theory

Journal of Philosophical Logic - Fitelson and McCarthy (2014) have proposed an accuracy measure for confidence orders which favors probability measures and Dempster-Shafer belief functions as...     

Religiosity and Excess Weight Among African-American Adolescents: The Jackson Heart KIDS Study

Recent studies suggest that religion and spirituality can yield health benefits for young African-Americans. We examined the relationship between religious practices, spirituality, and excess weight among African-American adolescents (N = 212) residing in the Deep South. Results from modified Poisson regression analysis indicate that adolescents who prayed daily had a lower prevalence of excess weight (PR 0.77 [95% CI 0.62–0.96]) than those who did not. This relationship was only significant for 12–15 year-old participants in age-stratified analysis. These findings suggest that preventive interventions offered to children and younger adolescents can have implications for weight status across the lifespan.

     

Effects of midbrain central gray lesions on spontaneous and electrically induced aggression in the rat

Large electrolytic lesions were placed in the midbrain central gray of male rats. Their effects on hypothalamically induced aggression, switch-off behaviour, and locomotion were investigated. A number of these animals were also tested for territorial intermale aggression in order to compare electrically induced and spontaneous aggression. Large lesions resulted in an increase of the current threshold to induce aggression by hypo-thalamic stimulation. Smaller, but still quite large, lesions decreased the threshold current for hypothalamic aggression. After the operation a decrease in the threshold for switch-off was present, both in the experimental and the control group. Current thresholds for locomotion were decreased after the lesions only in the experimental group. Spontaneous aggression was temporarily decreased after the lesion. No indication was found that other behavioural elements of the animal were distorted by the lesion. The parallel between the effects on spontaneous and electrically induced aggression makes it attractive to ascribe a role to the neural circuit of hypothalamus and central gray in territorial aggression. However, even with large lesions the animals were still capable of fighting, hence the central gray is not indispensable. An attempt was made to explain the differential effects that differently sized central gray lesions have on hypothalamic aggression.     

Visual target control of schedule-induced aggression in white king pigeons (columba livia)

Visual target control of schedule-induced attack was studied in domesticated pigeons by exposing them to successive and simultaneous target preference procedures involving a fixed-time food schedule and projected target images. Pigeons preferred attacking an image of a conspecific head over a headless bird regardless of the height of the latter. Images of an intact bird and of a head alone were equally effective in controlling attack and more effective than the headless bird. Neither the eye nor four. other head-related features exclusively controlled attack. The combined results suggest that the head of an intact conspecific target selectively controls schedule-induced attack and that the effectiveness of the head in directing attack is inversely related to its physical integrity as a unit without regard to specific features. These results are consistent with reports that the head and head-related features of an intruder control reproductive aggression in birds.     

Assessing interactional competencies: The early social-communication scales

Interactional competencies that develop in the first two years of life provide a foundation for all further social and communicative developments. Their normal acquisition, especially in the handicapped, can not be taken for granted. If delays in social-communicative development can be identified early in life and changes made in how the social environment interacts with the child, intervention may effectively facilitate social development. However, to accomplish this, both a model for describing and an instrument for assessing interactional competencies are needed. A recently developed set of scales, organized according to a cognitive-developmental framework and drawing upon recent research literature, is described in terms of its organization and content. Results that support the cognitive model underlying the set of scales are reported. The paper concludes with a consideration of potential criticisms that may apply to such a theoretically based instrument.     

COVID-19 and Religious Ethics

The editors of the JRE solicited short essays on the COVID-19 pandemic from a group of scholars of religious ethics that reflected on how the field might help them make sense of the complex religious, cultural, ethical, and political implications of the pandemic, and on how the pandemic might shape the future of religious ethics.