I am a very pessimistic person. I do my best, but I usually expect the worst outcome. I also see others in a similar way, and I barely expect anything from them. This is why when somethings turns out bad, I don't get too stressed over it, but when it does go well, it is a pleasant surprise.
In work, I've seen a lot of employees just do the bare minimum. Some even try to work as little as possible if they can. I think just having deliverables or targets is the best way to motivate employees. If they don't finish their deliverables on time, or they are below the target, then they are underperforming. If they finish it, then they just did their work. If they did more than was expected, then those are the ones I can look to promote. Most will just do the bare minimum and finish within the target. This makes it easy to look at the employee's performance, and identify the performers.