Showing papers by "Dorothy L. Cheney published in 2005"
TL;DR: Results suggest that male social instability itself does not necessarily elicit a stress response from females, rather, it is the specific male that rises to the alpha position that prompts astress response, and only from the females at risk for infanticide.
143 citations
TL;DR: GC variation in chacma males was primarily explained by temporary elevations following events that relate to reproductive fitness, and entering into a sexual consortship led to a temporary increase in a male’s GC measures.
124 citations
TL;DR: It is suggested that, in the earliest stages of language evolution, communication had a formal structure that grew out of its speakers’ knowledge of social relations that is referential, discretely coded, hierarchically structured, rule-governed, and propositional.
Abstract: If we accept the view that language first evolved from the conceptual structure of our pre-linguistic ancestors, several questions arise, including: What kind of structure? Concepts about what? Here we review research on the vocal communication and cognition of nonhuman primates, focusing on results that may be relevant to the earliest stages of language evolution. From these data we conclude, first, that nonhuman primates' inability to represent the mental states of others makes their communication fundamentally different from human language. Second, while nonhuman primates' production of vocalizations is highly constrained, their ability to extract complex information from sounds is not. Upon hearing vocalizations, listeners acquire information about their social companions that is referential, discretely coded, hierarchically structured, rule-governed, and propositional. We therefore suggest that, in the earliest stages of language evolution, communication had a formal structure that grew out of its speakers' knowledge of social relations.
121 citations
TL;DR: It is demonstrated that baboons' knowledge of their companions' social relationships is based on discrete-valued traits that are combined to create a representation of social relations that is hierarchically structured, open-ended, rule-governed, and independent of sensory modality.
119 citations
University of Delaware1, Case Western Reserve University2, Johns Hopkins University3, Columbia University4, Georgetown University5, University of Pennsylvania6, Harvard University7, University of California, Berkeley8, Tufts University9, Duke University10, University of Rochester11, Stanford University12, Massachusetts Institute of Technology13, University of Maryland, College Park14, Max Planck Society15
TL;DR: The authors consider the possibility that this research might alter the cognitive capacities of recipient great apes and monkeys, with potential significance for their moral status.
Abstract: The scientific, ethical, and policy issues raised by research involving the engraftment of human neural stem cells into the brains of nonhuman primates are explored by an interdisciplinary working group in this [Policy Forum][1]. The authors consider the possibility that this research might alter the cognitive capacities of recipient great apes and monkeys, with potential significance for their moral status.
[1]: http://www.sciencemag.org/cgi/content/full/309/5733/385
89 citations
TL;DR: Males in multi-male groups of chacma baboons in Botswana compete for positions in a linear dominance hierarchy and respond differently to male–male interactions in which they are not directly involved, using playbacks of the loud ‘wahoo’ calls exchanged between competing males in aggressive displays.
Abstract: Males in multi-male groups of chacma baboons (Papio hamadryas ursinus) in Botswana compete for positions in a linear dominance hierarchy. Previous research suggests that males treat different categories of rivals differently; competitive displays between males of similar rank are more frequent and intense than those between disparately ranked males. Here we test whether males also respond differently to male–male interactions in which they are not directly involved, using playbacks of the loud ‘wahoo’ calls exchanged between competing males in aggressive displays. We played paired sequences of vocal contests between two adjacently ranked and two disparately ranked males to ten subjects, half ranking below the signalers in the call sequences and half above. Subjects who ranked above the two signalers showed stronger responses than lower-ranking subjects. Higher-ranking subjects also responded more strongly to sequences involving disparately ranked, as opposed to adjacently ranked opponents, suggesting that they recognized those individuals’ relative ranks. Strong responses to sequences between disparately ranked opponents might have occurred either because such contests typically involve resources of high fitness value (defense of meat, estrous females or infants vulnerable to infanticide) or because they indicate a sudden change in one contestant’s condition. In contrast, subjects who ranked lower than the signalers responded equally strongly to both types of sequences. These subjects may have been able to distinguish between the two categories of opponents but did not respond differently to them because they had little to lose or gain by a rank reversal between males that already ranked higher than they did.
67 citations
TL;DR: In the Okavango Delta of Botswana, male chacma baboons (Papio ursinus) were observed to participate in chases and physical fights as discussed by the authors.
Abstract: We examined aggressive displays among male chacma baboons (Papio ursinus) over a 23-mo period in the Okavango Delta of Botswana. High-ranking males were more likely than middle- or low-ranking males to participate in displays. Regardless of rank, all males were more likely to participate in chases or physical fights if their opponent’s rank was similar to their own. Most chases and fights, including those that led to injuries, were also between similarly-ranked males. The rate of both aggressive displays and approachretreat interactions increased in the weeks before rank reversals, suggesting that rank challenges were preceded by a period when males assessed each others’ competitive ability and/or motivation. Aggressive displays between disparately-ranked opponents occurred most frequently in contests involving resources of high fitness value: the defense of meat, the defense of estrous females, and the protection of infants against infanticidal attacks. Silent displays were more likely to occur in these three contexts than were displays that occurred as part of more slowly escalating interactions, in which opponents first exchanged calls. Results suggest that competitive encounters among male baboons follow patterns predicted by evolutionary game theory.
31 citations