On this season of "The Apprentice," there is a new twist: the winning project manager doesn't automatically get immunity on the next task; rather, the winning PM get immunity only if a majority of the team votes that he/she should. The rule was no doubt inspired by last season's Michael, who got lucky, won as PM, then coasted the next week, and couldn't be fired even though the rest of his team was united against him.
Thus far, we've had two winning PMs. Markus and the men won the first task, but the men voted against giving Markus immunity. Marshawn and the women won the second task, and all of the women except Kristi (the week 1 women's PM) voted for giving Marshawn immunity.
This is interesting from a game theory perspective. You would think that a team member would rationally vote against giving immunity to the PM, since immunity only helps that PM and not the team member. Why increase the odds that you would be fired if your team loses?
Yet, the women voted for giving Marshawn immunity. I think the answer may lie in an analogy to the repeated Prisoner's Dilemma. In the one shot Prisoner's Dilemma, we know that the rational move for each player is to defect, even though both players end up worse off if they both defect. However, when the game is repeated indefinitely, cooperation can arise, and in fact, cooperating is the rational move. (When there are a finite number of games, it's rational to defect, but in real life, people may not think that far ahead.)
The team has to have a PM, and if you consistently vote against immunity for the winning PM, you won't get it when you win either. That decreases the incentive for anyone to be the PM.
So why didn't the men vote for Markus? He annoys the heck out of them.