Can we trust people to be good?

If people were stranded on a desert island I wouldn't trust them to survive because there is always one person who has to mess everything up for everyone then they all die. Even if there is food and water on the island somebody will need to step up and take change. If no one does that then they all die, or everyone want to be the leader of the whole group and there is a lot of arguing going on to find out who will be the leader. Only in a rare occasion one person will be the leader and everyone else will follow he or she. But eventually they will make a wrong choice and everyone will hate them. So they will try to pick someone else to be leader and they can't find the right person for the job. So they will not find food. they won't find water, they will start getting angry with each other, start fighting and all die. But i will never trust that people will be able to survive alone, even though it depends on a lot of thing most of the time they will not survive.