Same sex couples' successes and failures were studied alongside straight couples', and the bottom line is that same sex couples tend to operate from a healthier set of principles.
Emotional intelligence appears to be higher in same sex couples, where hostile and controlling emotional tactics were fewer. Humor and positive perspective were more often used to start disagreements, and disagreements were more easily forgotten when done. The research goes on to show the differences in lesbian couples' and gay couples' argument patterns, likely a result of gender socialization.
https://www.gottman.com/blog/what-makes-same-sex-relationships-succeed-or-fail/