Prior work has demonstrated that young children in the US and the Ecuadorian Amazon preferentially remember information about the dangerousness of an animal over both its name and its diet. Here we explore if this bias is present among older children and adults in Fiji through the use of an experimental learning task. We find that a content bias favoring the preferential retention of danger and toxicity information continues to operate in older children, but that the magnitude of the bias (...) diminishes with age and is absent in adults. We also find evidence that fitness costs likely impact the types of mistakes that participants make in their attributions of dangerousness and poisonousness. These results suggest that natural selection has shaped the way in which we learn and make inferences about unfamiliar animal species over ontogeny, and that future research is needed on how content biases may vary across the life course. (shrink)