How does cognition evolve? Phylogenetic comparative psychology.

Now more than ever animal studies have the potential to test hypotheses regarding how cognition evolves. Comparative psychologists have developed new techniques to probe the cognitive mechanisms underlying animal behavior, and they have become increasingly skillful at adapting methodologies to test multiple species. Meanwhile, evolutionary biologists have generated quantitative approaches to investigate the phylogenetic distribution and function of phenotypic traits, including cognition. In particular, phylogenetic methods can quantitatively (1) test whether specific cognitive abilities are correlated with life history (e.g., lifespan), morphology (e.g., brain size), or socio-ecological variables (e.g., social system), (2) measure how strongly phylogenetic relatedness predicts the distribution of cognitive skills across species, and (3) estimate the ancestral state of a given cognitive trait using measures of cognitive performance from extant species. Phylogenetic methods can also be used to guide the selection of species comparisons that offer the strongest tests of a priori predictions of cognitive evolutionary hypotheses (i.e., phylogenetic targeting). Here, we explain how an integration of comparative psychology and evolutionary biology will answer a host of questions regarding the phylogenetic distribution and history of cognitive traits, as well as the evolutionary processes that drove their evolution.

Increasing arousal enhances inhibitory control in calm but not excitable dogs

© 2015, Springer-Verlag Berlin Heidelberg.The emotional-reactivity hypothesis proposes that problem-solving abilities can be constrained by temperament, within and across species. One way to test this hypothesis is with the predictions of the Yerkes–Dodson law. The law posits that arousal level, a component of temperament, affects problem solving in an inverted U-shaped relationship: Optimal performance is reached at intermediate levels of arousal and impeded by high and low levels. Thus, a powerful test of the emotional-reactivity hypothesis is to compare cognitive performance in dog populations that have been bred and trained based in part on their arousal levels. We therefore compared a group of pet dogs to a group of assistance dogs bred and trained for low arousal (N = 106) on a task of inhibitory control involving a detour response. Consistent with the Yerkes–Dodson law, assistance dogs, which began the test with lower levels of baseline arousal, showed improvements when arousal was artificially increased. In contrast, pet dogs, which began the test with higher levels of baseline arousal, were negatively affected when their arousal was increased. Furthermore, the dogs’ baseline levels of arousal, as measured in their rate of tail wagging, differed by population in the expected directions. Low-arousal assistance dogs showed the most inhibition in a detour task when humans eagerly encouraged them, while more highly aroused pet dogs performed worst on the same task with strong encouragement. Our findings support the hypothesis that selection on temperament can have important implications for cognitive performance.

Citizen Science as a New Tool in Dog Cognition Research.

Family dogs and dog owners offer a potentially powerful way to conduct citizen science to answer questions about animal behavior that are difficult to answer with more conventional approaches. Here we evaluate the quality of the first data on dog cognition collected by citizen scientists using the Dognition.com website. We conducted analyses to understand if data generated by over 500 citizen scientists replicates internally and in comparison to previously published findings. Half of participants participated for free while the other half paid for access. The website provided each participant a temperament questionnaire and instructions on how to conduct a series of ten cognitive tests. Participation required internet access, a dog and some common household items. Participants could record their responses on any PC, tablet or smartphone from anywhere in the world and data were retained on servers. Results from citizen scientists and their dogs replicated a number of previously described phenomena from conventional lab-based research. There was little evidence that citizen scientists manipulated their results. To illustrate the potential uses of relatively large samples of citizen science data, we then used factor analysis to examine individual differences across the cognitive tasks. The data were best explained by multiple factors in support of the hypothesis that nonhumans, including dogs, can evolve multiple cognitive domains that vary independently. This analysis suggests that in the future, citizen scientists will generate useful datasets that test hypotheses and answer questions as a complement to conventional laboratory techniques used to study dog psychology.