Abstract: Studies on social animals often seek to identify dominance hierarchies, in which individuals are ranked according to competitive abilities based on counts of wins and losses in pairwise encounters. I illustrate Bayesian approaches, based on the method of paired comparisons, for determining ranks and for estimating relationships between dominance ability and other attributes. Bayesian inference combines prior probability distributions for each unknown parameter with likelihood functions to produce the joint posterior probability distribution for the quantities of interest. In contrast to nonparametric techniques for inferring ranks, Bayesian models yield measures of certainty for each inference and allow rigorous estimates of correlations between ranks and covariates even when there is considerable uncertainty as to the ranks themselves. A possible objection to the Bayesian approach is that it appears to entail more restrictive assumptions than do simpler methods. However, simulations show that Bayesian inferences are more robust to deviations from these assumptions than are the results of nonparametric methods.

Abstract: Idiosyncratic motor behaviour was investigated during four experimental procedures in 40 horses (males = 20, females = 20) to establish if horses revealed evidence of significant right or left laterality. The experimental procedures included (1) detection of the preferred foreleg to initiate movement (walk or trot), (2) obstacle avoidance within a passageway (right or left), (3) obstacle avoidance when ridden and (4) idiosyncratic motor bias when rolling. The influence of the horses' sex on both the direction and the degree of the laterality was explored within and between experimental procedures. The findings showed that the direction, but not the degree of idiosyncratic motor preference in the horses was strongly sex-related. Male horses exhibited significantly more (t = 3.74, d.f. = 79, P < 0.001) left lateralised responses and female horses exhibited significantly more (t = -6.35, d.f. = 79, P < 0.01) right lateralised responses. There was also significant positive correlation (P < 0.05) between four of six possible inter-experimental relationships. The results suggest two discrete trends of laterality associated with the sex of the horse. The primary cause of idiosyncratic motor laterality may be genetically predetermined, influenced by environmental factors or a combination of these two and the current findings may support the development of sex-specific training schedules for the horse. Further, work in this area might assist in defining the mechanisms of brain hemisphere lateralisation and allocation of cognitive function in the horse.

Abstract: Although this bookis focusedon the cognitive neuroscience ofhuman social behaviour, an
understandingofsocial cognition in non-human animals is critical for unravellingthe neural basis of
social cognition in humans as well as the selective pressures that have shapedthe evolution ofcomplex
social cognition. Thanks to methodological limitations, we know little about the relationships between
certain biochemical andelectrophysiological properties ofthe human brain andhow theycompute the
behaviour andmental states ofother individuals. Traditional techniques for examiningneural function
in humans, such as event-relatedpotentials (ERP),positron emission tomography(PET),and
functional magnetic resonance imaging(fMRI),are constrainedbythe fact that subjects are placed
either into an immoveable scanner with a lot ofbackgroundnoise or wiredup with dozens of
electrodes that are sensitive to slight movements. The possibilityofscanningor recordingbrain waves
from two individuals that are physicallyinteractingsociallyis technicallyimpossible at present
(however, see Montague et al, 2002 for a new methodfor simultaneouslyscanningtwo individuals
interactingvia a computer).
The onlywayto understandthe neurocognitive architecture ofhuman social behaviour is to examine
similar social processes in both human andnon-human animal minds andmake comparisons at the
species level. An additional argument is that traditional human socio-cognitive tasks are dependent on
the use ofstories, cartoons andverbal cues andinstructions (Heberlein & Adolphs, this volume)which
themselves will elicit specific neural responses that have to be eliminatedfrom neural responses
specificallyrelatedto mindreading. Therefore, the development ofnon-verbal tasks wouldprovide a
breakthrough for studies in non-linguistic animals, pre-verbal human infants andhuman cognitive
neuroimaging.

Abstract: In Pavlovian conditioning, animals acquire a response to a previously neutral stimulus (conditioned stimulus, CS), such as a light, if that stimulus predicts a biologically important event (unconditioned stimulus, US), such as delivery of food. Learning typically occurs when the CS precedes the US (forward conditioning), and not when the CS follows the US (backward conditioning). In social learning about predators, the predator stimulus is considered to be the CS to which observers acquire avoidance responses after the stimulus has been presented in contiguity with an alarmed demonstrator, the US. We tested the prediction that social learning of response to a predator would occur even if the social alarm cues (the US) appeared before the predatory stimulus (the CS). Carib grackles, Quiscalus lugubris, responded to a familiar predator presented at close range by suppressing alarm calls. Presentation of an unfamiliar avian model (black-and-yellow pigeon) also decreased calling, and this inhibition of calling was enhanced following a training session in which the model stimulus was presented in association with grackle alarm calls. Acquired inhibition of calling was independent of the order of presentation of the model and an alarm chorus. These are the first results to indicate that social acquisition of predator avoidance is not dependent upon a particular temporal relationship between predators and social alarm cues. Evolution may have modified some properties of Pavlovian conditioning to accommodate social learning about potentially dangerous stimuli.