It is always dangerous to generalize, and particularly so with client psychology. Good articles on the subject can provide useful introduction and instruction on the topic, in particularly an article by Gary A. Williams and Robert B. Miller titled ‘Change the way you persuade’ in the Harvard Business Review.
 

Williams and Miller, who ran a U.S. customer-research firm, interviewed 1,684 executives over a two year period, dividing them into five different types. Although the study took place over a decade ago, these different categories can still be easily recognized:
 

1. Charismatics (25% of those studied)

The authors describe such people as “initially exuberant about a new idea or proposal but will yield a final decision based on a balanced set of information”. They advise you use clear results-orientated language to get them excited, but also present a balanced argument because charismatics may have had bad experiences in the past making impulsive decisions, which they will be worried about repeating.
 

2. Thinkers (11%)

“Can exhibit contradictory points of view within a single meeting and need to cautiously work through all the options before coming to a decision," according to Williams and Miller. You need to appeal to thinkers’ intelligence, by presenting them plain facts and not being too pushy, which could lead them to distrust you.
 

3. Skeptics (19%)

This group, warn Williams and Miller “remain highly suspicious of data that doesn’t fit with their worldview and make decisions based on their gut feelings”. Such ‘strong personalities’ need to be handled with care, and you need to establish credibility quickly: an endorsement or referral by someone they trust is an obvious way to do this.
 

4. Followers (36%)

“Make decisions based on how other trusted executives, or they themselves, have made similar decisions in the past”, argue the authors. They suggest you show followers your solid track record, and use language which emphasizes reliability, without being too patronizing about it – no-one would say they themselves were a follower.
 

5. Controllers (9%)

This final group “focuses on the pure facts and analytics of a decision because of their own fears and uncertainties”. Controllers may also be the hardest to persuade. Williams and Miller conclude that “in practice, the only way to sell an idea to controllers is not to sell it”; simply supply them with the information to let them convince themselves.

Read Williams and Miller’s full article on the Harvard Business Review’s website.