You yell and he shuts down. Or, you're the screamer and she passive-aggressively lobs grenades back at you over her impenetrable wall. Either way, the problems never get solved and the relationship takes another hit. This is your downward spiral... your bad deal.
Why do we do this? Because we're neurologically programmed to. These are the instinctual responses that locked in during childhood to keep us safe and to ensure we'll be cared for. And when we were small, they worked in our family of origin. But now, we take the same strategies and inflict them on our partners. And these are not the strategies of adults; they are the strategies of scared children; children who don't care about the consequences of their actions, so long as the internal alarm bells stop ringing.
These alarm bells are not subtle. They are all-hands-on-deck, brace-for-impact alarm bells. Cortisol and adrenaline flooding the system, making rational thought very difficult. "GET THIS GUY TO STOP YELLING AT US!" Or, "MAKE HER LOVE US!" So our little 5 year-old soldier springs into action with the only set of tools he or she knows: yelling, passive-aggression, withdrawal, martyrdom, etc. etc.. "Don't worry, I'll yell back and make it stop." Or, "Don't worry, we can just run away and the bad feelings will go away". So the alarm bells stop, but the residual damage to the relationship piles up with each repeat of the spiral.
So how do we stop the downward spiral? Simple. We learn to go against instinct.
When cortisol is released, the intensity of the feeling is as bad as being chased by a lion through the jungle or as intense as being abandoned on a floating iceberg. Even if all that's actually happening is that you're arguing with your spouse about the dishwasher. So in that moment, self-talking yourself off the cliff, so to speak, is the only way to not to let your instinctual response escalate the situation and do damage to the relationship. "This sensation I am feeling; the lump in my throat or pit in my stomach; the warmth in my chest or pressure in my head; this sensation is the calling card of my childish behavior. And I choose to interrupt that pattern and try to process this like an adult."
Why don't we do this? Because fighting instinct is emotionally and physically exhausting. We have so much practice doing the old thing. The new thing flies in the face of instinct, like teaching a dog to sit and wait when a bone is 4 feet in front of it. Can the dog do it? Yes, with practice. Can you not scream but instead stay solutions-oriented when your partner is (in your judgement) treating you poorly? Yes, with practice.
So, to fix your relationship in two easy steps:
1. Go against instinct.
2. Repeat ad infinitum.