Alien abduction

I've never had a sim be abducted by aliens before in TS4-- rotten luck perhaps in the past, with well over 1000 hours played, but I've had 3 sims in the last week abducted by aliens in the same family. I thought this was a bug, but I see @babajayne's comment stating the chances for abduction are increased with a Scientist in the household, which for the first time ever, I have! So next question, is it going to decrease back to normal if he quits that career?