I find that when you're in that situation, you fall into the trap that most women fall into. You explain too much. People take it as "Oh, she's not sure. She's trying to convince HERSELF, not me. She's still talking so that means it's still up for discussion."
Honestly? Stop talking. The answer is "No. 6 months." turn and walk away. They aren't interested in the new research. They aren't interested in learning something. Know your audience. If you know they're entrenched in their opinions, accept that, agree to disagree and walk away. As long as you keep arguing, so will they.
