I have a population of 30 and a lot of scientists working for tech points. They keep going off to do things like relax, go swimming, exercise, look at the boulder, etc. They didn't use to do this before. Why did they start now, and is there any way to stop it?

It happens as they become lexx anxious about food.. As your food supply moves further over 1000, 1500, the "quality" of life improves.
As for stopping it - that depends on if you'd like someone to stop you watching tv, going to a game, shopping etc.. lol

My male scientists keep deciding to do laundry when I make them research; the female ones keep researching. Well until I accidently drop someone on them and they decide to go to the Love Shack.