1. The Depressive Pessimist will complain that the task that they're doing isn't enjoyable, and make statements doubting the group's ability to succeed.
2. The Jerk will say that other people's ideas are not adequate, but will offer no alternatives himself. He'll say "you guys need to listen to the expert: me."
3. The Slacker will say "whatever", and "I really don't care."
Anyway, they found that in almost all cases the presence of a 'bad apple' could bring down the performance of the whole group, except where the group had an exceptional leader who could overcome this drawback.
Coincidentally happytune and I were just discussing a person at work who I described as 'poison' - she is like the touch of failure. Luckily we have very little to do with her, but we know her colleagues are finding it a real challenge to work with her.
Being self-critical I know I can be both a pessimist and a slacker on a bad day, and I'm going to try to think twice before I make comments like that.
I think there are worse types of bad apple than those though - much worse. The worst are the ones who try to get other people into trouble, who try to glom all the credit, who deliberately misunderstand and cause trouble, who make poisonous remarks. Actively psychopathic team members. And I've never found a way to deal with people like that - just RUN AWAY.