Do you like to be told what to do? Most people don’t and that is why saying “You should” is a top emotional trigger phrase.
Starting a sentence with “You need” implies that you are superior in your thinking to the other party, and the other party doesn’t appreciate feeling belittled.
Many counselors suggest using “I” statements yet my research has found that this doesn’t mitigate the negative effect of feeling inferior. For example, telling you spouse “I think you need to take out the garbage more often” implies that you have superior garbage management skills. Your spouse will free angry and frustrated which leads to resistant behavior.
Rephrasing to a consultative, problem solving approach such as “I would like to find a solution that works for both of us about the garbage situation?” will lead to a cooperative, problem solving conversation rather than an attack-defense spiral.
Social psychology research shows that people are more cooperative when they feel consulted and part of the process, instead of dictated to.