The toughest part about marriage might be the "I do."
Because once unions become long-term, they have their best chance at being a solid relationship, according to research conducted by UC Berkeley over the last 25 years.
According to research begun in 1989 by psychologist Robert Levenson, couples who use the word "we" have a better shot at solving fights, wives "matter more" when settling conflict -- and though the 15-year mark is key for a long-term, healthy union, DNA also plays a role, according to university research.
People who "get through the first 15 years of marriage learn to value each other," Levenson said. "They are not longer engaged in futile attempts to change one another."
Oddly, marriage therapists also did a poor job of deciding who would be divorced, he said.
The research was conducted via video interviews with 156 couples recorded every five years. Some died, some divorced, but enough survived to give us some knowledge about love and marriage.