Criticizing your partner is different than offering a critique or voicing a complaint. The latter two are about specific issues, whereas the former is an ad hominem attack. It is an attack on your partner at the core of their character. In effect, you are dismantling their whole being when you criticize.
Not necessarily terminal, but paves the way for the other horsemen.
When we communicate in this state, we are truly mean—we treat others with disrespect, mock them with sarcasm, ridicule, call them names, and mimic or use body language such as eye-rolling or scoffing. The target of contempt is made to feel despised and worthless.
Research even shows that couples that are contemptuous of each other are more likely to suffer from infectious illness (colds, the flu, etc.) than others due to weakened immune systems! Contempt is fueled by long-simmering negative thoughts about the partner—which come to a head when the perpetrator attacks the accused from a position of relative superiority.
The single greatest predictor of divorce.
Typical response to criticism.
When we feel unjustly accused, we fish for excuses and play the innocent victim so that our partner will back off. Unfortunately, this strategy is almost never successful. Our excuses just tell our partner that we don’t take their concerns seriously and that we won’t take responsibility for our mistakes
Typical response to contempt.
Rather than confronting the issues with their partner, people who stonewall can make evasive maneuvers such as tuning out, turning away, acting busy, or engaging in obsessive or distracting behaviors. … And unfortunately, stonewalling isn’t easy to stop. It is a result of feeling physiologically flooded, and when we stonewall, we may not even be in a physiological state where we can discuss things rationally.