Saying no is simple and hard at the same time. The words are simple but often it takes courage to say them.
How you say no is important to the result. If you say no in a weak powerless way you are likely to get overridden. If you say no in a hard-edged aggressive way you are likely to alienate the other person.
Saying no in an assertive style validates the other person’s needs and desires while setting firm boundaries around what you will and won’t do.
There are two basic steps to saying no in an assertive way:
Validate the other person’s needs and desires
State a clear preference not to do it
The ideal structure is illustrated in these examples: “Action movies with a high body count are exciting, but I’d prefer something peaceful”; “I can see the attraction of getting a case of beer, but I’d rather not drink any alcohol tonight”; “I know you still enjoy smoking weed, but I’m not comfortable with it anymore”.
McKay et al (2007) make the case that it is better not to provide any justification for your position because this can give the other person ammunition to use against you if they try to persuade you to change your mind. No-one can argue with straightforward feelings and preferences.