The hidden triggers in humans
Cialdini starts his book by describing how easily animal behaviour can be manipulated due to many preprogrammed 'tapes' which, once triggers make animals perform crazy things (e.g. mother turkey killing her own chicks under certain conditions - lack of a specific sound). Cialdini states many parallels with the human's automatic actions that can be triggered.
One example is having a reason. If a person joins a queue saying: "Excuse me, may I use the Xerox machine, I have five pages", only about half of the people in the line would let the person skip it. But if he just adds any reason to his phrase, 94% of people would allow him to use the machine (e.g. Excuse me, may I use the Xerox machine, I have five pages and I am in a rush").
While it may appear that the difference is in the 'because I'm in a rush' point, it turns out that it is not. In reality, the keyword is 'because'. The third type of request was formulated like this: Excuse me, I have five pages. May I use the Xerox machine because I have to make some copies? Incredibly, but nearly all (93%) agreed, even though no real reason was added to justify their compliance.
Another vital experiment that Cialdini describes at the beginning of the book is the following one:
A man has three bowls of water in front of him. One has hot water, the other is cold, and the third bowl has room temperature. After the person puts one of his hands in a bowl with cold water and the other - in a hot-water bowl, he would be shocked that when both of his hands are in the third bowl, one of his hands would feel like it is in hot water, while the other hand (exactly in the same bowl) would feel that it is in the cold. As Cialdini notes, "the point is that the same thing…can be made to seem very different, depending on the nature of the event that precedes it".
To show how this principle can be exploited in real-life situations, Cialdini provides the following example:
"Suppose a man enters a fashionable men's store and says he wants to buy a three-piece suit and a sweater. If you were the salesperson, which would you show him first to make him likely to spend the most money? Clothing stores instruct their sales personnel to sell the costly item first. Common sense might suggest the reverse: If a man has just spent a lot of money to purchase a suit, he may be reluctant to spend much more on purchasing a sweater. But the clothiers know better. They behave by what the contrast principle would suggest: Sell the suit first because when it comes time to look at sweaters, even expensive ones, their prices will not seem as high in comparison. A man might baulk at spending $95 for a sweater, but if he has just bought a $495 suit, a $95 sweater does not seem expensive".