From time to time we need to be vulnerable. When you share your secrets, and being vulnerable, this is the key to connect with people fast, this is called the vulnerability effect. Each of us is the centre of our universe. Vulnerability is attractive, mistake humanise us. Vulnerability sounds like truth and feels like courage.
The author also explain about the Franklin effect. The Franklin effect is when you had done something for other people and you thank them, they are more likely to help you again, or do you a favor.