Abstract: The terms sociallearning and social influence have been used descriptively and theoretically to characterize a broad range of animal behavior from physical antipredatory adaptations such as eye spots, which are totally under genetic control, to the human capacity for the exaggeration of individual characteristics, known as caricature, which are largely under cognitive control. In the present review, the various forms of social influence and social learning are identified and distinghished from imitation, a term that generally has been reserved for behavioral matching that cannot be accounted for using simpler specifically predisposed, motivational, or learning mechanisms. It is suggested that much of the ambiguity in the literature concerning the various forms of social learning can be attributed to the distinction between the function of a behavior and the mechanisms responsible for its occurrence. Finally, the various mechanisms that have been proposed to account for imitative learning are presented and an attempt is made to evaluate them.

Abstract: Seven experiments were conducted on four miniature pigs to determine: (1) whether the pigs can discriminate between people wearing the same coloured clothing; (2) what cues they rely on if they could discriminate. For 2 weeks before the experiments began, the pigs were conditioned in a Y-maze to receive raisins from the rewarder wearing dark blue coveralls. They were then given the opportunity to choose the rewarder or non-rewarder in these experiments. Each session consisted of 20 trials. Successful discrimination was that the pig chose the rewarder at least 15 times in 20 trials (P<0.05: by χ2-test). In Experiment 1, both rewarder and non-rewarder wore dark blue coveralls. By 20 sessions, all pigs successfully identified the rewarder. In Experiment 2: (1) both wore coveralls of the same new colours or (2) one of them wore coveralls of new colours. They significantly preferred the rewarder even though the rewarder and/or non-rewarder wore coveralls of new colours. In Experiment 3, both wore dark blue coveralls but olfactory cues were obscured and auditory cues were not given. The pigs were able to identify the rewarder successfully irrespective of changing auditory and olfactory cues. In Experiment 4, both wore dark blue coveralls but covered part of their face and body in different ways. The correct response rate decreased when a part of the face and the whole body of the rewarder and non-rewarder were covered. In Experiment 5, both wore dark blue coveralls and changed their apparent body size by shifting sitting position. The correct response rate increased as the difference in body size between the experimenters increased. In Experiment 6, the distance between the experimenters and the pig was increased by 30 cm increments. The correct response rate of each pig decreased as the experimenters receded from the pig, but performance varied among the pigs. In Experiment 7, the light intensity of the experimental room was reduced from 550 to 80 lx and then to 20 lx. The correct response rate of each pig decreased with the reduction in light intensity, but all the pigs discriminated the rewarder from the non-rewarder significantly even at 20 lx. In conclusion, the pigs were able to discriminate between people wearing coveralls of the same colour after sufficient reinforcement. These results indicate that pigs are capable of using visual cues to discriminate between people.

Abstract: This experiment examines the cues used by cattle to discriminate between people, particularly the role played by facial cues. We trained and tested eight Holstein cows 5 days each week for 2 months. For each cow, we used two people, a rewarder and a non-rewarder, of different size and dressed in overalls of the same colour. The operant chamber was a large box within which stood the two people. The cow could see, smell and touch each person. A lever was placed in front of each person. When the cow pushed the lever in front of the rewarder, it received 75 g of concentrate and nothing when it pushed on the other one. For each test session, the cows made 10 choices. The placement of the people was determined randomly according to the Gellerman series. The success criterion was defined as at least eight correct choices out of 10 trials for two consecutive sessions (binomial law P<0.003). During the shaping, seven cows out of eight learned to press the lever to obtain the food. The cows were then tested in a series of 10 trials with only the rewarder present. Seven out of seven cows succeeded in reaching the success criterion. In experiment 1, both the rewarder and the non-rewarder were present and standing upright at normal height and in full view of the cow. Five out of seven cows achieved the success criterion. In experiment 2, the cows could see only the faces of the two people. None of the cows were able to reach the success criterion. In experiment 3, both people were present standing up and wearing identical masks that completely covered their heads. Five cows out of five achieved the success criterion. In experiment 4, we changed the relative height of the people. Five cows out of five succeeded when the two people stood so they were of equal height but with their faces visible. However, no cows succeeded when the people were both of equal height and had their faces covered. This study suggests that cows seem to use multiple cues to discriminate between people. Cows appear able to use either body height or the face to discriminate between people but use of the face alone is more difficult when the cows cannot see the rest of the body.

Abstract: It is believed that environmental enrichment techniques can play an important part in creating suitable captive environments for horses. There has, however, been little scientific investigation into the effectiveness of 'stable-toys' which claim to reduce the performance of equine stereotypies. This study investigated the effect of a foraging device known as 'The Equiball' on equine stereotypies. Six horses were given their evening feed in an Equiball, and the occurence of stereotypic behaviour recorded using scan sampling of video observations. Pre-enrichment, horses spent a mean(SD) of 5.27 ? 8.17 per cent of their time in the stable performing stereotypies; and significant individual variation in mean time performing stereotypic behaviour was found (P < 0.05). Several peaks in stereotypy over the day were found, the two main ones corresponding to the times before feeding. A reduction in stereotypic behaviour in five horses, and a small increase in stereotypic behaviour in one horse was observed during enrichment. During enrichment, there was an overall trend for stereotypic behaviour to decrease (P < 0.1). When used in conjunction with other measures such as behaviour therapy, companionship, increased exercise, and so on, the Equiball may help to create an environment less likely to lead to the development of stereotypic behaviours.