Yesterday, Eric Solotoff blogged about the phenomenon of the New Years Resolution Divorce. It happens. I encourage you to read that post prior to the one below because it provides some useful background on the issue:

It's the New Year. A time filled with resolutions, promises to change, and commitments to begin anew. Your marriage is no exception. You're fed up – the affairs, the reckless spending or the mistreatment. You've determined that this is your year to finally take the road to singles-ville, to start a new life free of this weight you've been carrying around for years.

But...what happens your resolution to break free of your spouse coincides with your spouse's resolution to recommit to the relationship? He promises things will be different; she will take steps to treat you better; he'll pitch in more with the children; the "extracurricular activities" will stop. Your spouse promises he/she will magically morph into a different person. All of a sudden, your jaded, tired, fed up self is looking at your future model spouse. And now you're in a quandary.

So the question becomes, which one of you wins the war of the resolutions? Science says, if you're looking for a complete personality overhaul, think again.

Brian Little, a professor of psychology at Cambridge University and author of Me, Myself, And Us: The Science of Personality and the Art of Well-Being stated in a 2014 interview that in adulthood, your personality becomes pretty much set in stone.

You can thank your parents for that; many of our personality traits have a very strong genetic component, which remains constant throughout much of our lives. However, in your teens and twenties, your personality matrix evolves rapidly while you mature. As people enter their thirties and beyond, those traits solidify; change slows to a crawl and requires far more effort, according to Paul T. Costa Jr., scientist emeritus at the laboratory of behavioral science at the National Institutes of Health.

The situation becomes even more complex when dealing with a personality disorder, such as Narcissistic Personality Disorder (NPD). This is because NPD had a serious environmental component – it emerges from an environment in which vulnerability feels dangerous to the person. In turn, insecure attachment styles emerge, where fears of depending on anyone result in attempts to control the relationship or avoid intimacy altogether. For people with NPD, change would mean unlearning a whole host of feelings that are ingrained in them and they subconsciously believe keep them safe.

Essentially, asking or expecting a person to change would be asking them to act "out of character" – an unremitting show where he or she plays a part for your benefit. Little, says, however, that this act has a serious effect on the automatic nervous system, somewhat akin to anxiety. You heart rate quickens, your muscles tense – as if you're experiencing a stress reaction. Eventually, you revert back to yourself because the whole process of morphing into another person can be both physically and mentally taxing.

The amount of time a person can play another character has yet to be studied. But the question is, do you want your marriage to be the test case?

Now, that is not to say that people have not successfully improved marriages that once were on the precipice of the abyss. However, odds are, if you think your spouse is going to assume a completely different personality to save your marriage, you may just lose the war of the resolutions.

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.