Small talk is usually engaged in with people that one doesn't know very well, whereas more substantive conversation is with people you do have a deeper relationship with. So wouldn't it be possible that the different levels of happiness are more connected to your different level of connection with the person you're talking to? I think that's actually a really good point. You want to make sure that it's really the conversation itself that's moving your feelings around. And there've been some experimental studies where you can get people to be self disclosing, vulnerable, talking about deep things that are emotional and close to your values and so forth.