Response particles, like English ‘yes’ and ‘no’, are used to respond to polar questions or assertions and are found in all languages. However, the number of particles and the specific meanings they convey vary across languages. For example, in some languages particles mainly convey whether the response itself is positive or negative, while in others they convey whether the response is agreeing or disagreeing with previous discourse. Further, some languages have two response particles, while others have three, or even four. Recent work suggests that how meanings tend to be mapped to forms cross-linguistically might nevertheless be constrained. Roelofsen & Farkas (2015) suggest that indicating disagreement with a negative question or assertion (e.g., A: ‘Ally doesn’t eat meat.’ B: ‘Yes, he does.’) is more marked than indicating agreement with a positive assertion (e.g., A: ‘Ally eats meat.’ B: ‘Yes, he does’.). This difference in semantic markedness is argued to lead to a difference in form: more marked meanings are mapped to more specialized forms. Here we investigate this hypothesis in a series of behavioral experiments. Across our experiments, we find that participants are indeed sensitive to the differences in meaning that particles can convey. However, we fail to find evidence for all differences implicated by the hierarchy hypothesized in Roelofsen & Farkas (2015), and our results highlight an unexpected special role for Positive Agreement—the least marked meaning.