This I must admit, is something that I am guilty of. It's so much easier to put the blame back on my partner than it is to recognize that I am wrong- yes, I said it, I can be wrong. Often times this is the hard part. 
        The third horseman is defensiveness. You usually become defensive when you feel unjustly accused or attacked by your partner. It's quite natural to have this response because internally you may feel threatened or stressed. You may also feel unappreciated or a need to "defend" your own honor. Defensiveness drives you into a mode of "you against me". When this happens, even a seemingly neutral comment may be taken as an attack. During a conflict, being defensive conveys that you are not taking your partner seriously or hearing them out. This is the point where defensiveness affects the relationship. Often times, it can even ignite an argument that was completely avoidable. 
Example of a defensive statement: 

• Your partner says "Honey, you forgot to go buy some milk today." 
• You respond: "I was just too darn busy today. As a matter of fact you know just how busy my schedule was. Why didn't you just do it?" 

Not only did you respond defensively, but you turned the table and made it your partner's fault. If this sounds familiar, you are not alone. Yep, not my proudest moment either. 
A non-defensive response would have been: 
"Oops, I forgot. I should have asked you this morning to do it because I knew my day would be packed. There's next week." 
    Although completely reasonable to defend yourself in the example above, defensiveness does not help your communication. In fact, you may find your partner saying things to you such as "I can't tell you anything because you always get mad." If you find yourself often denying responsibility, making excuses, or lashing back with a complaint of your own during a conflict, then most likely you have uttered those words "it's not my fault" as well. 

The 2nd horseman that can lead down the path of destruction in your relationship is contempt. Think back to your most recent argument with your partner. If you heard an exchange of insults or sarcastic mockery, then there was contempt in your argument. 
You are in contempt if you are using name calling, insults, sarcasm, or eye rolling when you argue with your partner.  People who engage in contempt are often talking down to their partner, express superiority, and take a position of "better than thou".  Contempt usually follows criticism and it is even more destructive to your relationship.  Contempt attacks your partner's sense of self. It breeds more resentment and hostility in the relationship. It conveys disrespect and makes it even more difficult to resolve problems.
What to do: 
when there is contempt in a relationship, this usually indicates that resentment has already built a nest in the relationship.  Unlike criticism, the best remedy for contempt is recognizing it in yourself, acknowledging the harmfulness of this behavior, and letting go of anger which fuels the contempt. If your partner is the one who expresses contempt, this is much more difficult to remedy. But there is hope. Your partner and you can practice taking a time out or cooling off when things are getting heated in an argument before the insults are delivered. Of course, you could also seek professional counseling.

What usually goes on that drives relationships down the path of doom? This blogpost is the first of a series of posts that will highlight for you why many marriages and relationships fall apart. These are known as the four horsemen of the apocalypse (Gottman & Gottman). 

What is the difference between a criticism and a complaint in a relationship? Well, there is a BIG difference. Criticism is the first horseman of doom. In a relationship criticism attacks the core of your partner. It attacks their character and who they are, not the behavior that they are engaging in. In the long run, criticism creates a wedge of animosity in the relationship. Having animosity makes it more difficult to forgive, care, and appreciate in a relationship. If you ever wondered why saying something like "you never pick up after yourself" or "you never think about my feelings" has the opposite effect on your partner, then this is the reason. Criticism in this way does not motivate your partner to change their behavior. It simply shuts their ears off each time you start to say something. Criticism  sends a message to your partner that you don't care for their feelings or acknowledge them. 

What to say instead: Express specific behaviors that bother you and request or tell your partner what you would want them to do instead. 
Example: 
Criticism: You always make decisions without me. You are such an inconsiderate person! 
Say instead: When you changed our plans without talking to me first, I felt hurt. I would like for us to talk about changing our plans together next time.