Andy usually tries to answer jokingly.
Sometimes he'll answer honestly (he does this on talk shows). But usually he tries to think of a way to answer with a joke (or a story that might be funny).
There are several reasons for this, but I think the first is expectations.
It's strange. People expect him to give great or interesting answers. And they expect him to be hilarious all the time. So he (like many comedians) has found that if he turns it on and answers with jokes, then that meets expectations well. But if he gets vulnerable and honest (as some comedians have) then he gets judged more, and he becomes the "unfunny comedian."
So it's almost like a defensive mechanism that comedians use. I even saw Aubrey Plaza go through this. For her first 6 months to a year once she was "discovered," she answered interview questions honestly and transparently. But then she started sounding a little uninteresting or whiny, some media folks pointed to it, and it probably frustrated her a little. Then she started showing up at interviews as her April character, being stone cold, emotionless, and saying silly and crazy things.
Essentially, Andy landed at the same place (trying to make people laugh in interviews), but it was natural for him to get there (he was always there).
Other more traditional actors "talk their craft" more, almost like politicians do, where their guard is bringing it back to their work as actors and actresses (because they're not expected to be funny). It's really quite interesting.
Andy tries to make the person asking the questions laugh. It's like a game he plays with himself, whether or not he can get them on the first question or how long it takes for him to get them.
In one interview, his interviewer asked her first question, "What's your favorite color?" Andy thought hard for a second or two, and then he said, "Blend." She laughed hysterically and Andy said, "Got you! Nailed you on the first question!"
It really is a game for him.
- TAE