Mixing business & emotions

Everyone likes to project that they're great business people and can handle almost any situation with skills an savvy. Yet, today, I'm literally in the middle of a business negotiation where two opposite parties are in a stalemate because they're allowing their emotions to get in the way of concluding a mutually beneficially agreement.

The two entities are “mad” at the opposite side, believe they're being lied to and don't seem able to act with pragmatism and with a cool head to achieve a deal that would be in their best interest. So what gets in the way? Immature emotions, big ego and poor judgment; at the same time they pretend and would like to project that they're are top when it comes to business; I'd laugh if I had no vested interest in the outcome!