Does the chimpanzee have a theory of mind? 30 years later

On the 30th anniversary of Premack and Woodruff's seminal paper asking whether chimpanzees have a theory of mind, we review recent evidence that suggests in many respects they do, whereas in other respects they might not. Specifically, there is solid evidence from several different experimental paradigms that chimpanzees understand the goals and intentions of others, as well as the perception and knowledge of others. Nevertheless, despite several seemingly valid attempts, there is currently no evidence that chimpanzees understand false beliefs. Our conclusion for the moment is, thus, that chimpanzees understand others in terms of a perception-goal psychology, as opposed to a full-fledged, human-like belief-desire psychology.     

Do apes and children know what they have seen?

Chimpanzees and young children understand much about what other individuals have and have not seen. This study investigates what they understand about their own visual perception. Chimpanzees, orangutans, and 2.5-year-old children were presented with a finding game in which food or stickers were hidden in one of two or three tubes. We varied whether subjects saw the baiting of the tubes, whether subjects could see through the tubes, and whether there was a delay between baiting and presentation of the tubes to subjects. We measured not only whether subjects chose the correct tube but also, more importantly, whether they spontaneously looked into one or more of the tubes before choosing one. Most apes and children appropriately looked into the tubes before choosing one more often when they had not seen the baiting than when they had seen the baiting. In general, they used efficient search strategies more often than insufficient or excessive ones. Implications of subjects' search patterns for their understanding of seeing and knowing in the self are discussed. Accepted after revision: 7 January 2001 Electronic Publication     

A comparison of sources of baseline data for treatments of problem behavior following a functional analysis

It is common practice in research on the treatment of problem behavior to compare levels of targeted behaviors during treatment to levels when treatment is not in place. Some researchers use data collected as part of a multielement functional analysis as the initial baseline, whereas others collect new baseline data following completion of the functional analysis. We evaluated whether the source of baseline data influences the reliability and efficiency of decision-making. Results suggest that similar decisions are made in regard to treatment efficacy using the different sources of baseline data, but using data from a multielement functional analysis as baseline may save time. Interrater agreement was adequate, but lower for some graphs than has been observed in past studies. Several potential explanations for this discrepancy are discussed.     

A comparison of rate‐based and latency‐based assessments for determining demand aversiveness

Demand assessments are used to determine the relative aversiveness of demands. This study compared two demand assessments (i.e., rate‐based and latency‐based) proposed in past research with three children with intellectual and developmental disabilities. We compared the hierarchical outcomes of demand aversiveness and efficiency of the two assessments. Differing degrees of correspondence between the assessments was found across participants. The latency‐based measure was most efficient for a participant with high‐rates of problem behavior. The rate‐based assessment was more efficient for a participant with low‐rates of problem behavior. More research is needed to determine when the different assessments should be conducted.     

Estudio socio-espacial de las relaciones de afinidad en un grupo de gorilas (Gorilla,gorilla, gorilla) cautivos

Resumen

El uso del espacio refleja las relaciones que existen entre los individuos de un grupo. La afinidad entre el macho adulto y las hembras adultas es importante para que los grupos de gorilas sean estables. Se han estudiado las relaciones de afinidad en un grupo de 5 gorilas (1 macho adulto, 3 hembras adultas y 1 hembra joven) mediante medidas espaciales. Los resultados indican que existe una baja cohesión grupal, donde el macho no se distingue por tener las relaciones fuertes con las hembras adultas. La hembra joven es la más afín al macho y a las demás hembras. Las relaciones entre las hembras adultas son débiles. Posibles explicaciones a los resultados y algunas consideraciones metodológicas son discutidas.     

A COMPARISON OF BRIEF FUNCTIONAL ANALYSES WITH AND WITHOUT CONSEQUENCES

Variations to traditional functional analysis methodology, such as brief functional analyses (BFAs), are prevalent in the literature. In the current evaluation, two types of BFAs were each conducted with five participants. In one, potential motivating operations (MOs) were presented, and problem behavior resulted in delivery of an associated consequence. In the other, the same MOs were presented, but no consequences were delivered. Results of the two BFAs were compared with respect to the conditions in which problem behavior occurred and the degree of differentiation between test and control conditions. Results across the BFA methodologies generally matched across all five participants. However, greater differentiation was observed in the BFA that did not include consequences. Copyright © 2012 John Wiley & Sons, Ltd.     

Do domestic dogs interpret pointing as a command?

Domestic dogs comprehend human gestural communication flexibly, particularly the pointing gesture. Here, we examine whether dogs interpret pointing informatively, that is, as simply providing information, or rather as a command, for example, ordering them to move to a particular location. In the first study a human pointed toward an empty cup. In one manipulation, the dog either knew or did not know that the designated cup was empty (and that the other cup actually contained the food). In another manipulation, the human (as authority) either did or did not remain in the room after pointing. Dogs ignored the human’s gesture if they had better information, irrespective of the authority’s presence. In the second study, we varied the level of authority of the person pointing. Sometimes this person was an adult, and sometimes a young child. Dogs followed children’s pointing just as frequently as they followed adults’ pointing (and ignored the dishonest pointing of both), suggesting that the level of authority did not affect their behavior. Taken together these studies suggest that dogs do not see pointing as an imperative command ordering them to a particular location. It is still not totally clear, however, if they interpret it as informative or in some other way.     

Monkeys perform as well as apes and humans in a size discrimination task

Whether the cognitive competences of monkeys and apes are rather similar or whether the larger-brained apes outperform monkeys in cognitive experiments is a highly debated topic. Direct comparative analyses are therefore essential to examine similarities and differences among species. We here compared six primate species, including humans, chimpanzees, bonobos, gorillas (great apes), olive baboons, and long-tailed macaques (Old World monkeys) in a task on fine-grained size discrimination. Except for gorillas, subjects of all taxa (i.e. humans, apes, and monkeys) were able to discriminate three-dimensional cubes with a volume difference of only 10 % (i.e. cubes of 50 and 48 mm side length) and performed only slightly worse when the cubes were presented successively. The minimal size discriminated declined further with increasing time delay between presentations of the cubes, highlighting the difficulty to memorize exact size differences. The results suggest that differences in brain size, as a proxy for general cognitive abilities, did not account for variation in performance, but that differential socio-ecological pressures may better explain species differences. Our study highlights the fact that differences in cognitive abilities do not always map neatly onto phylogenetic relationships and that in a number of cognitive experiments monkeys do not fare significantly worse than apes, casting doubt on the assumption that larger brains per se confer an advantage in such kinds of tests.     

A retrospective analysis of the relation between resurgence and renewal of behavior targeted for reduction

Functional communication training (FCT) is an evidence-based treatment for behavior targeted for reduction that often combines extinction for target responses and arranges functionally equivalent reinforcement for alternative behavior. Long-term effectiveness of FCT can become compromised when transitioning from clinic to nonclinic contexts or thinning reinforcement schedules for appropriate behavior. Such increases in targeted behavior have been conceptualized as renewal and resurgence, respectively. The relation between resurgence and renewal has yet to be reported. Therefore, the present report retrospectively analyzed the relation between renewal and resurgence in data collected when implementing FCT with children diagnosed with developmental disabilities. We found no relation when evaluating all 34 individuals assessed for resurgence and renewal or a subset of individuals exhibiting both resurgence and renewal. These findings suggest that one form of relapse may not be predictive of another form of relapse.