A multivariate view of cognitive performance reveals positive correlation in the Trinidadian Guppy (Poecilia reticulata)

Abstract

Cognitive variation is common among-individuals within populations, and this variation can be consistent across time and context. From an evolutionary perspective, among-individual variation is important and required for natural selection. Selection has been hypothesised to favour high cognitive performance, however directional selection would be expected to erode variation over time. Additionally, while variation is a prerequisite for natural selection, it is also true that selection does not act on traits in isolation. Thus, the extent to which performance covaries among specific cognitive domains, and other aspects of phenotype (e.g. personality traits) is expected to be an important factor in shaping evolutionary dynamics. Fitness trade-offs could shape patterns of variation in performance across different cognitive domains, however positive correlations between cognitive domains and personality traits are also known to occur. Here we aimed to test this idea using a multivariate approach to characterise and test hypothesised relationships of cognitive performance across multiple domains and personality, in the Trinidadian guppy (Poecilia reticulata). We estimate the among-individual correlation matrix (ID) in performance across three cognitive domains; association learning in a colour discrimination task; motor cognition in a novel motor task and cognitive flexibility in a reversal learning task, and the personality trait ‘boldness’ measured as time to emerge. We found no support for trade-offs occurring, but the presence of strong positive domain-general correlations in ID, where 57% of the variation is explained by the leading eigen vector. While highlighting caveats of how non-cognitive factors and assay composition may affect the structure of the ID-matrix, we suggest that our findings are consistent with a domain-general axis of cognitive variation in this population, adding to the growing body of support for domain-general variation among-individuals in animal cognitive ability.

Artificial selection for reversal learning reveals limited repeatability and no heritability of cognitive flexibility in great tits ( Parus major )

“…Following the hypothesized trade-off between learning and cognitive flexibility, animals that are quick at forming initial associations learn subsequent similar information less well [21][22][23]. Several studies have investigated both the phenotypic correlations between and the heritability of associative and reversal learning performance [24][25][26][27][28][29][30][31]. Current evidence suggests low to moderate heritability of reversal learning performance across species, but how it relates to associative learning appears to vary between species.…”