Random observation

One of the questions in the General Social Survey is:  "If you were to get enough money to live as comfortably as you would like for the rest of your life, would you continue to work or would you stop working?"  While looking for something else in the GSS the other day, I noticed this question and wondered if there was any trend.   One thing led to another, and here are trends by educational level (college graduate or not):

The likely reason that more educated people would be less likely to stop working is that they have more satisfying jobs.   Job satisfaction has stayed about the same in both groups over the whole period, so that doesn't account for the difference in trends.  On the other side, more educated people presumably have more interests outside of work--maybe that gap has grown, although I'm not sure why it would.  Or maybe it reflects changes in the sense of moral obligation to work?