Says persuasion can be a science, not an art. The authors aim to “provide the reader with a better understanding of e psychological processes underlying how we can influence others to move their attitudes or behaviors in a direction that results in a positive outcomes for both parties”; includes ethical strategies to persuade others, as well as what to look out for to resist covert and overt influences on our decision making.

My take aways:
Think better of others
Honesty is still the best policy
Give before expecting to receive
How you say it is just as important as what you say

Book is general enough, yet with clear examples to allow reader to infer best easy to approach. See or

Cites Colleen Szot, infocommercial writer, who changed the phrase “operators are waiting, please call now” to “if our operators are busy, please call again”.

Social proof – encouraging hotel towel reuse. Put 2 different signs. One was the basic message about saving the environment. Another was the fact that majority of hotel guests reused their towels at least once during their stay. Found 26% were more likely to reuse their towels when told about the “social proof”. When they changed the second message to say that majority of guests in the same room did so, the rate increased to 33%. Also suggests the more similar the persuader tithe target audience, the higher the chance of persuasion.

Social proof also explains why a message may self destruct. E.g. When a negative social proof/ behaviour is being used (littering) which may backfire to show many ppl are doing so (i think issue is also the message implies there is no consequence) and the viewer may think it’s ok to continuing littering. Same reason explaining why voter turnout continues to fall when politicians condemn the low turnout. Or the high numbers of ppl who don’t show up for their appointments.

Another interesting case study. The Arizona Petrified Forest Natural Park. They experimented with different messages to deter theft of the petrified wood. The control was a no-sign (2.92% loss of the planted petrified wood), a no-stealing sign (1.67%) and a sign/ illustration saying many people have taken the wood and destroyed the natural state of the forest (7.92%).

Power consumption example. Power of group norms, the “magnetic middle”. Those who consumed above and below average all gravitated towards the middle. By adding positive feedback to the latter, they were able to make them maintain their lower consumption.

Stating the value of things people are getting for free (e.g. You are getting $150 worth of consultation for free Vs you are getting free consultation)

Offering two differently priced products, from same company, may make the less expensive one seems better choice.

(crisis comms) That when communicating dangers (e.g. Health messages or health threat), there should be offering of courses of action or options in clear and specific steps. If not, or by being vague, ppl tend to receive the message with denials, fear or blocking it out.

Power of social obligations and reciprocity (why Iceland granted citizenship to Bobby Fischer). Suggests instead of asking, “Who can help me?”, the long term view is to ask “Whom can I help” and this may result in reciprocal behaviour later.

The sticky note experiment. More ppl bothered to complete the survey when it is accompanied by a handwritten note Vs cover letter or no letter (lowest response). Suggests the more personalized the effort, the more likely they will respond/ agree.

Post-meal mints/ higher tips experiment: it’s the recipient’s perceived significance (not necessarily costly) of the gift; the manner in which the gift is given; the unexpectedness.

A variation of the hotel towel reuse experiment. Reciprocation-based Vs incentives-based (former had 45% higher response): Hotel already made donations to an environmental protection agency, and telling guests it did so on their behalf. Gave impression the guests initiated the efforts. Suggests higher tendency for reciprocal behaviour when we offer help that is genuine and completely unconditional.

(Francis Flynn) study found ppl who did favors tend to increase the value of their deeds while recipients perceived lower value as time goes by. suggests opposite tendencies. Implications: giver could suggest/ remind how recipient would have returned the favour, or start by subtly reminding earlier favor before asking a return favor, e.g. “did you find the report I sent you earlier useful?”

The road safety signboard experiment. Found that getting ppl to start with small steps resulted in higher participation in greater subsequent commitment.

Positive labeling as a way to persuade. E.g. “.. sense there is good in you”; “you seem the type to do the right thing”

Asking people to affirm their commitment (to a desirable behaviour) tends to increase their participation. E.g. From “please call to cancel” to “will you call if you wish to cancel?”

Benjamin Franklin; his way to make a fellow legislator amicable to him was to ask the other person for a favor first (rather than to give one first). Suggest that if the other person agreed, he/ she will find ways to justify why you are worth helping. If they reject, you are no worse off.

“captainitis”. Assuming someone knows best because they are most experienced. Transcript of the downed 1982 Air Florida flight 90 reinforces the point; exchange between co-pilot and captain, where co-pilot spotted the error but deferred to the captain’s erroneous decision, in spite of confirming the fault on the instruments.

Suggests familiarity/ association tends to lead to persuasion. E.g. Same name, same school. Suggests to start with stating commonalities before discussions with other party. Or, naming children after characters (e.g. Harry) may inspire them to read up (Harry potter).

Restaurant waiters study. Higher tips received by those who repeat the orders than those who merely say OK. Suggests Imitation as the basic form of persuasion. Implication for customer service.

Benjamin Franklin: “search others for their virtues”. By reacting positively to others, the other party is more likely to reciprocate. (think better of others)

Notion of loss (scarcity) may be more compelling than gain. E.g. Telling ppl they stand to lose 50 cents a day tends to be more effective than telling them about saving 50 cents more.

Xerox study; unique motivational influence of the word ‘because’. Found that in a queue to copy, ppl tend to let requests through if the requestor phrased the request with the word ‘because’ and with a reason, no matter how weak (“… Because i’ve to make copies”). But need for valid reason increased when the stakes were increased to more pages. Suggests persuasion requires strong rationale to be stated even if it appears fairly clear.

Asking ppl to name 10 reasons (why they should use a pdt) was less effective in creating a favourable impression than asking them to name just one. The former was associated as harder.

Rhymes tend to persuade/ create favourable impressions (which explains why rhyming jingles seem to be popular).

Idea of perceptual contrast. More favourable if you give them a “benchmark” that offers a contrast. E.g. A $7000 spa package Vs $100,000 to construct and maintain one.

Carwash incentive experiment; redeem a stamp if they pay for each car wash. One group had a 8-stamp requirement. The other had a 10-stamp requirement but 2 pre-stamped. more ppl completed the incentive for the latter. Suggests ppl more inclined to participate/ continue with prg if they have evidence that they already made progress.

Suggests that less-than-straightforward sounding names, but readable and pronounceable, can be more appealing.

An experiment with mirrors in a room; ppl more likely to behave if they see themselves or think they can be seen. Same principle with name tags (removing anonymity). Experiment, at a honor-based payment system pantry, with a poster with & without a pair of eyes; the ones that had was more likely to get ppl to pay up.

Study suggests ppl who feel sad are more likely to be susceptible to suggestions; implication is to give ourselves time to consider big decisions. For the persuader, while we may gain an upper hand if we tap onto the sad emotive state of the other party, it will not lead to longer term positive relationships, as the other party will later see the situation as being exploitative or they regret the transaction.

Emotions make ppl less sensitive to magnitude of numbers and more likely to pay attention to the presence or absence of events. For businesses, implies ppl are more likely to pay attention to the presence or absence of emotional-laden offers than actual numbers involved.

Sleep deprivation leads to less than ideal decision-making (get enough sleep!) Ppl who have had their caffeine-fix are more likely to be persuaded (with good arguments) than when they are not mentally stimulated.

Cited US Cellular’s “no email on Fridays” policy. Two employees discovering, over phone, they were just across the hall rather than states (sounds extreme to me, but maybe they are a gigantic org)

Email Experiment found that by disclosing personal info to the other negotiating party, there was greater likelihood of an outcome. Found that women were more persuaded in person while form of communication makes less difference for men (but experiment didn’t explore gender difference of persuader).

A communication experiment (email, voice, face to face) found that all groups tend to overestimate the likelihood of the other party perceiving their message exactly. But the gap for the email group was highest.

Diffusion of responsibility; why mass mails fare worse in getting responses than mails sent to individuals.

Consumer research experiment; buying sofa. Website background that suggested economic value (pennies) tend to persuade ppl to select based on cost, and a background that suggested comfort (clouds) tend to have ppl select based on perceived comfort/ quality. Respondents insist they were not influenced by any suggestions though the facts indicate we may be more susceptible to unconscious clues than we think.

Conclusions There may be cultural differences, e.g. Reciprocity may differ according to diff cultural values. Citibank study: Americans tend to look at individual reciprocity; Spanish look at relationships; mainland chinese look at rank and hierarchies.

Individualistic Vs collectivistic cultures. Implication on business, relating to ppl, advertising and marketing. For the latter, the authors suggest it’s necessary to credit the group rather than just the individual, especially in encouraging reciprocal actions. Suggests that relationships may be more important/ have more emphasis in collectivistic cultures, while individualistic culture may tend to focus more on the efficiency of the message.

References include sources from:
Robert B. Cialdini, 2001 influence: science and practice, 4th Ed.
Journal of personality and social psychology
Journal of consumer psychology
Journal of consumer research
Journal of experimental social psychology
Journal of applied psychology Psychological Science Personality and social psychology bulletin

Update: excellent summary of the points in the book, here, by Martin Poulter.