Other than that I think its about even between: feeling respected, wanted for who you are, listened to, understood, sex, feeling connected, and a large number of others. Most of those are largely affect by communication.
Become offended easily and makes it difficult to communicate.
Expect perfection from the other one. When we marry a person, we know very well he has good qualities, and bad personality traits. Some people just focus on the bad ones. The more you want to change the other one, the more frustrated you both become.
Complaining and nagging really makes the other one feel annoyed, and it doesn't help the situation. The more complaining and nagging you do, the more damage you do about your marriage and your own popularity.
Some people take the other one for granted, and think you deserve their giving just because of the rings and certificates, it is a very wrong attitude to have, both of the man and woman have to share the responsibilities in a marriage.
Underlying personality issues - borderline personality disorder (1st exw), narcissism, OCD, depression and poor communication - in particular failure to listen, and failure to respect your spouse's concerns (stbxw).
My GF, a MSW, LCSW and counselor to truly mentally ill people for many years, says - "I can't believe your stbx let you go - she must be crazy".
The GF might be a little crazy herself, but that's another issue.
As for me I'm not sure if crazy is the right word to describe me, a desire for very good sex and lots of expressed appreciation with emotional intimacy are essential to this man.
#1 Sex -Mismatched Libidos - lazy lovers, frigid lovers , wham bam lovers, rejecting spouses, Moms sleeping with the kids, etc
#2 Finances - if a poor Spender marries another Poor spender, the Hell of bill collecting awaits & living from run down dive to another. If a Saver marries a spender, the Fighting begins.
#3 Communication -If a Silent Treatment partner marries one who can't live like that, it creates anger in one , resentment in the other.
Physical abuse, Mental abuse, Unforgiveness, keeping secrets from each other, Addictions, debilitating Depression, various mental illnesses, complacency leading to total boredom, Loss of physical attraction, not fullfilling the others Love languages , Religious differences, Toxic inlaws, Putting others before your spouse, Workaholicism, a severe Mid Life Crisis, and the list goes on....