What’s the difference between the the Maters and Disasters?

In The Seven Principles for Making Marriage Work, John Gottman describes two types of couples: the Masters and Disasters.

The Masters remain happily married, while the Disasters either break up or stay together and are unhappy.

What’s the difference between the two? 

Disasters struggle with conflict. They use the Four Horsemen and they have a hard time repairing.

Masters understand that conflict is inevitable. They manage it by listening to each other’s needs and expressing empathy.

source: Gottman Institute