BACKGROUND Bystander affiliation (post-conflict affiliation from an uninvolved bystander to the conflict victim) may represent an expression of empathy in which the bystander consoles the victim to alleviate the victim's distress ("consolation"). However, alternative hypotheses for the function of bystander affiliation also exist. Determining whether ravens spontaneously offer consolation to di...

Complex social life has been proposed as one of the main driving forces for the evolution of higher cognitive abilities in humans and non-human animals. Until recently, this theory has been tested mainly on mammals/primates, whereas little attention has been paid to birds. Indeed, birds provide a challenge to the theory, on one hand because they show high flexibility in group formation and comp...

We examined the influence of the availability of human food on the distribution and foraging habits of the Common raven (Corvus corax), in yosemite national Park, California. the raven arrived and established itself as a year-round resident in yosemite in the 1960s, and its population has been increasing ever since. Surveys of nine sites with varying levels of human influence in yosemite sugges...

Woodward and Goodstein (1) discussed the handling of data that do not support a given hypothesis. They illustrated their point as follows: an investigator might inductively infer, after observing a large number of black ravens, that all ravens are black. According to the inductive approach, good scientific practice consists in recording all that one observes and not just some selected part of i...

To investigate the characteristics of PCBs that are linked to cognitive functioning, those congeners that were concurrently found in 271 Mohawk adolescents were grouped according to structure (dioxin-like or non-dioxin-like) and persistence (persistent or low-persistent). After the effects of the congener groups were orthogonalized, regression analyses (controlling for a number of variables fou...

Woodward and Goodstein (1) discussed the handling of data that do not support a given hypothesis. They illustrated their point as follows: an investigator might inductively infer, after observing a large number of black ravens, that all ravens are black. According to the inductive approach, good scientific practice consists in recording all that one observes and not just some selected part of i...

OBJECTIVES The purpose of this study is the evaluation of how the decline of cognitive abilities caused by aging is moderated by biologically determined personality dimensions: Neuroticism (N) and Extraversion (E). MATERIALS AND METHODS The research was conducted with the participation of 160 men in good physical health, professional drivers, aged 20-70 (Mean = 40, SD = 11). Personality trait...

Complex social life requires individuals to recognize and remember group members and, within those, to distinguish affiliates from nonaffiliates. Whereas long-term individual recognition has been demonstrated in some nonhuman animals, memory for the relationship valence to former group members has received little attention. Here we show that adult, pair-housed ravens not only respond differentl...

Avian urban colonization is thought to be facilitated by a capacity for innovative feeding, ecological generalism and social foraging. However, the relative importance in exploiting urban resources and avoiding urban predators of being inherently ‘pre-adapted’ to the urban environment or adjusting to it through phenotypic plasticity requires more examination. These issues were explored in a nat...

Generics are sentences such as “tigers are striped,” “lions have manes,” and “mosquitoes carry West Nile virus.” Generics express generalizations, but unlike quantified statements, generics do not carry information about howmany members of the kind or category have the property. For example, if asked “how many ravens are black?” one could reply “all [or some, or most, etc] ravens are black,” bu...