In this study we use Brownian dynamics (BD) to investigate a model activated reaction. We simulate varying activation energy using the probability of reaction on collision. We find that, as the reaction probability decreases (activation energy increases), local structural effects are seen more strongly at ever higher density. In the limit of very low values of the reaction probability, local structural effects on reactivity are seen over the entire density range studied. This provides clear evidence that the degree to which activation energy affects a chemical reaction correlates directly with the extent to which solute-solute correlations may influence that reaction.