Because people assume "you are what you say you are", they talk a lot to become acquainted with each other. (Para. 3)
Meaning: Because people believe that they can judge a person by what he is talking about, they talk a lot to become familiar with each other.
The word "assume" means "to accept or believe that something is true even though you have no evidence".
Most people assume the lack of success is the result of his carelessness. 大部分人都认为他的失败是粗心的结果。
When the teacher saw the two students talking during the exam, she assumed they were discussing the answers and got angry. 当老师发现两个学生在考试中交谈时，就以为他们在讨论答案，为此很生气。