With wedding season in full swing, America's newlyweds stand to learn from the experts: older adults whose love has endured job changes, child-rearing, economic certainty, health concerns and other life challenges.

Filling our knowledge gap on finding a mate and remaining married, Cornell gerontologist Karl Pillemer completed the Cornell Marriage Advice Project, the largest in-depth interview study ever done of people in very long unions, surveying more than 700 individuals wedded for a total of 40,000 years. The findings are detailed in Pillemer's book, "30 Lessons for Loving: Advice from the Wisest Americans on Love, Relationships, and Marriage."

To capture the voice of lived experience, Pillemer conducted a random national survey of nearly 400 Americans age 65 and older, asking how to find a compatible partner and other advice on love and relationships. In subsequent in-person interviews with more than 300 long-wedded individuals -- those in unions of 30, 40, 50, or more years -- Pillemer captured more insights for overcoming common marriage troubles. His team interviewed divorced individuals, too, asking how others might avoid marital breakups.

The average age of interviewees was 77 and included 58 percent women and 42 percent men. The average length of marriage in the sample was 44 years; the couple with the longest marriage were ages 98 and 101 and had been married 76 years. Responses were coded into the most commonly occurring recommendations, resulting in a list of the most frequently selected lessons for a successful, long-term relationship.

"Rather than focus on a small number of stories, my goal was to take advantage of the 'wisdom of crowds,' collecting the love and relationship advice of a large and varied cross-section of long-married elders in a scientifically reliable and valid way," said Pillemer.

Pillemer uncovered common advice for couples walking down the aisle or decades into marriage. The top five lessons from the elders, along with Pillemer's analysis:

Learn to communicate: "For a good marriage, the elders overwhelmingly tell us to 'talk, talk, talk.' They believe most marital problems can be solved through open communication, and conversely many whose marriages dissolved blamed lack of communication."

Get to know your partner very well before marrying: "Many of the elders I surveyed married very young; despite that fact, they recommend the opposite. They strongly advise younger people to wait to marry until they have gotten to know their partner well and have a number of shared experiences. An important part of this advice is a lesson that was endorsed in very strong terms: Never get married expecting to be able to change your partner."

Treat marriage as an unbreakable, lifelong commitment: "Rather than seeing marriage as a voluntary partnership that lasts only as long as the passion does, the elders propose a mindset in which it is a profound commitment to be respected, even if things go sour over the short term. Many struggled through dry and unhappy periods and found ways to resolve them -- giving them the reward of a fulfilling, intact marriage in later life."

Learn to work as a team: "The elders urge us to apply what we have learned from our lifelong experiences in teams -- in sports, in work, in the military -- to marriage. Concretely, this viewpoint involves seeing problems as collective to the couple, rather than the domain of one partner. Any difficulty, illness, or setback experienced by one member of the couple is the other partner's responsibility."

Chose a partner who is very similar to you: "Marriage is difficult at times for everyone, the elders assert, but it's much easier with someone who shares your interests, background and orientation. The most critical need for similarity is in core values regarding potentially contentious issues like child-rearing, how money should be spent and religion."

According to Pillemer, "These unique insights show the value of using rigorous survey methods to uncover the practical wisdom of older people. Although a number of general studies of elder wisdom have been conducted, no one had researched the specific advice elders have for a critical life domain like marriage. Therefore, the study points the way toward the need for future research on concrete lessons we learn over the course of our lives."