Habitat and social context affect memory phenotype, exploration and covariance among these traits

Individual differences in cognitive ability are predicted to covary with other behavioural traits such as exploration and boldness. Selection within different habitats may act to either enhance or break down covariance among traits; alternatively, changing the environmental context in which traits are assessed may result in plasticity that alters trait covariance. Pond snails, Lymnaea stagnalis, from two laboratory strains (more than 20 generations in captivity) and F1 laboratory reared from six wild populations were tested for long-term memory and exploration traits (speed and thigmotaxis) following maintenance in grouped and isolated conditions to determine if isolation: (i) alters memory and exploration; and (ii) alters covariance between memory and exploration. Populations that demonstrated strong memory formation (longer duration) under grouped conditions demonstrated weaker memory formation and reduced both speed and thigmotaxis following isolation. In wild populations, snails showed no relationship between memory and exploration in grouped conditions; however, following isolation, exploration behaviour was negatively correlated with memory, i.e. slow-explorers showing low levels of thigmotaxis formed stronger memories. Laboratory strains demonstrated no covariance among exploration traits and memory independent of context. Together these data demonstrate that the relationship between cognition and exploration traits can depend on both habitat and context-specific trait plasticity. This article is part of the theme issue 'Causes and consequences of individual differences in cognitive abilities'.