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. 大部分人都認為他的失敗是粗心的結果。
When the teacher saw the two students talking during the exam, she assumed they were discussing the answers and got angry. 當老師發現兩個學生在考試中交談時，就以為他們在討論答案，為此很生氣。