In that case, why not use the "method of color" ?
This method is based on the results of research conducted by American psychologist William Marston (1893-1947) who published in 1928 "Emotions of normal people " .
Marston distinguishes four profiles in individuals: Dominant, Influential, Steady, Compliant (DISC). Each profile is assigned a color: red, yellow, green, blue.
Note: no color is superior to another. Each individual (customer) with a color has strengths and weaknesses.
on this assumption, a trade negotiator led even formed can easily guess the color of the caller and adapt its behavior.
RED
- His behavior: Dominant
- Its values: materialism and individualism
- Its engine: the challenges
- Her main emotion: anger
- Tactics to adopt: be factual, go to the essentials, quickly conclude by giving your partner the feeling that it decides.
THE YELLOW
- His behavior: Influential
- Its values: harmony and beauty
- Its engine: human contacts
- Her main emotion: joy
- Tactics to be adopted: let your partner express themselves, develop a friendly attitude, do not clutter the technical details but focus on innovation, in case of crop digression politely.
GREEN
- His behavior: Stable
- Its values: humanitarian
- Its engine: cooperation
- His main emotion: sadness
- Tactics to be adopted: win his confidence, but be patient directive.
BLUE
- His behavior: Conformist
- Its values: intellect and tradition
- Its engine: the search for rational solution
- His main emotion: fear
- Tactics to adopt: Do not try to make a friend, bring a lot of written material, reassure your partner with numbers, graphics, technical aspects.
In conclusion: A psychological approach simple and fun who knows a true success in business.