Human Nature
We are funny creatures, we humans. We have put men on the moon and nearly wiped out polio on the face of the earth, but when faced with the elevator not coming as fast as we like, we press the button over and over thinking it might speed things up a bit. If I am waiting at the elevator with you, I have already made several assumptions about you and your need to get where you're going as quickly as possible. First impressions are very important in social engineering. You have approximately 8 seconds before people will have a solid impression of who you are, and it is difficult to overcome a first impression.
Social engineering is practiced every day by everyone in every walk of life. If you have ever had a job interview, you attempted to social engineer the interviewer into giving you the job. If you have ever had a first date, you were attempting to make someone like you enough to go on a second one. Social engineering is when person A attempts to manipulate person B...