What motivates players to cooperate?

[Rob_Hasty]

Purely personal gain - it is way more likely someone will actively try to help you, provided that you helped them first.

Totally agree, you have to ally with someone for a better personal gain. You can't be the best in everything so better to find people who are good at the things you are bad. This was the first thing in business life: cooperate or fail. I was always some kind of an introvert but it really doesn't work out in business life. I even witnessed to 5 people who hate each other are working together to sell a real estate in Budva and succeed. Main point is to having the ability of cooperate.