"Once we have made a choice or taken a stand, we will encounter personal and interpersonal pressures to behave consistently with that commitment."

A commitment is most powerful when it is:

• Active: actions (writing it down) speak louder than words (saying it aloud).
• Public: due to a drive to look like a consistent person, viewed as a positive personality trait.
• Effortful: the more effort goes in to it, the greater its ability to influence.
• Made in the absence of outside pressures: such as threats or rewards.

"We view a behaviour as more correct to the degree that we see others performing it."

Social proof is most powerful under the conditions of:

• Uncertainty: when we are unsure of ourselves, or when the situation is unclear or ambiguous, e.g. the bystander effect.
• Similarity: when we are observing the behaviour of people just like us.

"We most prefer to say yes to the requests of someone we know and like."

The factors that reliably cause liking are:

• Physical Attractiveness: we automatically assign favourable traits such as talent, kindness, honesty and intelligence to good-looking individuals.
• Compliments: even if it is known the flatterer stands to gain something.
• Contact: or, familiarity.
• Cooperation: working towards a common goal.
• Association: the opposite of the tendency to dislike someone who brings us bad news. The positive connection does not have to be logical.

"We are willing to go to almost any length on the command of authority."

In the absence of genuine authority, the appearance of authority is enough:

• Titles: usually take years of work to earn, but can be easily adopted without proof.
• Clothing: such as tailored suit or a uniform.
• Trappings: such as luxury cars or jewellery.

"Opportunities seem more valuable to us when their availability is limited."

Scarcity is most powerful when combined with:

• Censorship: we hate to lose freedoms we already have, so we react against the interference by wanting the item more than before e.g. access to censored information.
• Recent Loss: we value things that have only recently become less available to us more e.g. revolutions after a period of economic growth, followed by a sharp reversal.
• Rivalry: we value something most when we are in competition for it e.g. another potential buyer for a property.