Mediator, attorney and BigSpeak’s EVP Ken Sterling will be the first to tell you that deal making is almost always all about logic: data, pros and cons, solid numbers. But what happens when you try to male a deal with someone who has become so emotionally invested in a certain outcome, rationality goes out the window?

This can be the result of a fixed mindset, in which one negotiation partner is wholly focused on only one potential outcome and will. Not. Budge.

Sterling compares this to when a child and parent argue over a lollipop. The parent presents plenty of reasonable explanations as to why the child cannot have the lollipop, such as impending dinner, the child already having eaten some candy, etc, which the child promptly ignores– they still want their lollipop. So, what can you do?

For his full insights, check out his most recent article for Inc, in which he lays out his 4-step method for working around fixed-mindset situations.