The psychology of pronouns

Psychologist James Pennebaker studies the psychology of word choice. Among other things, he has discovered that lower status people use the word 'I' more when talking to higher status people. Pennebaker illustrates this with an email that he wrote to a high-status professor before making this discovery:

Dear Famous Professor: 

The reason I'm writing is that I'm helping to put together a conference on [a particular topic]. I have been contacting a large group of people and many have specifically asked if you were attending. I would absolutely love it if you could come... I really hope you can make it. 

Jamie Pennebaker

 And here is the professor's reply:

Dear Jamie - 

Good to hear from you. Congratulations on the conference. The idea of a reunion is a nice one ... and the conference idea will provide us with a semiformal way of catching up with one another's current research.... Isn't there any way to get the university to dig up a few thousand dollars to defray travel expenses for the conference? 

With all best regards,

Famous Professor