The broad focus of my dissertation has been investigating the various selection pressures contributing to the variation we observe in animal cognition, and how that variation evolves. Thus far, my work has primarily investigated how divergence in habitat breadth contributes to variation in decision-making and learning; more specifically, how environmental variability influences the evolution of these cognitive abilities. Highly variable environments are predicted to favor higher decision-making and learning abilities (because those are the environments where they are hypothesized to be the most adaptive), while uniform environments are predicted to favor more “hardwired” or “rules of thumb” based approaches. To investigate this, we are comparing two closely-related species of fruit flies that recently diverged in diet breadth (and thus have been under divergent selection for the degree of environmental variability experienced in nature), Drosophila simulans and Drosophila sechellia. Divergence in habitat breadth and the degree of environmental variability experienced in nature are predicted to influence the evolution of general cognitive abilities (i.e., whether you have the general ability to make decisions and learn). However, due to divergent evolutionary histories, not all stimuli in the environment have equal consequences for everyone. So, when animals begin to diverge in cognition, does this divergence generalize across a broad range of cognitive abilities, stimuli, and contexts? Or is divergence in cognition limited to certain cognitive abilities, stimuli, or contexts? The central focus of my work has been understanding how selection pressures influence the evolution of cognition to produce variation on cognitive outcomes, and whether that divergence generalizes across cognitive abilities and stimuli, or is limited to certain cognitive abilities and contexts.