How do two people make love last? A Cornell University survey gathered information and insights from hundreds of Americans over the age of 65 who share one common trait: they've all created sustainable marriages. Some of their tips, such as “learn to communicate,” may be unsurprising, while other points, such as “choose a partner who is very similar to you,” might disappoint the more adventurous. Crowd-sourced wisdom may not be the most nuanced instruction book, but still, the value of this advice is obvious.

Dr. Karl Pillemer, a gerontologist, and his colleagues conducted an in-depth study of people in very long unions, in order to gain an understanding of the essential skills and behaviors necessary to stay on track in a marriage. A random national survey of 400 Americans, the Cornell Marriage Advice Project included in-person interviews with more than 300 people in marriages of 30, 40, and 50 or more years. The research team also spoke with divorced people to learn from them as well.

More than half (58 percent) of interviewees were women, while the average age of survey participants was 77. The couple who had been married longest had traveled life's highways and byways together for 76 years, yet the average length of wedded bliss among the sample was 44 years. After completing their many interviews, the researchers gathered the data, analyzed the results, and compiled a list of the most frequently occurring recommendations for a long-term relationship.

According to Pillemer, the elders cited the following five suggestions most often:

Communicate

The long-married seniors described their success as due to open communication. Learning how to talk with your partner and speak your mind in a not hurtful way is key to sticking together. Interestingly, divorced participants frequently reported a lack of communication may have eroded their marriages, and so they essentially corroborated this good advice.

Know Your Partner Well Before Marrying and Don't Expect Them To Change

In this instance, many of those surveyed gave the opposite advice as to what they themselves had done — married young. Interestingly, the surveyed elders suggested younger people wait before marrying in order to learn more about their partners. According to Pillemer, the senior citizens also emphasized it is a mistake to assume you can change your mate.

Respect Your Marriage as a Lifelong, Unbreakable Commitment

Marriage is voluntary and it’s most definitely a choice, however, it’s also a "till-death-do-you-part" commitment. Wedlock is not meant to be disposed of once the passion dies or when things get rough. Couples who work through their unhappy times together often find ways to resolve their differences. Years later, they even may find themselves nestled inside a surprisingly fulfilling marriage.

Two are one

Once two people are married, problems, difficulties, or illnesses happen not to one person but to two people — the married couple. Similarly, success and joy also happens for the couple. Partnership is about sharing and learning to work together in your collective best interest. Me must end once we comes to town.

Select a mate who is similar to you

Marriage, the seniors say, is easier with someone who shares your interests and background. Similarity with regard to core values, such as child-rearing and finance, is especially important and will smooth the road in countless ways.

These five nuggets taken directly from the horse’s mouth — actually many horses’ mouths — point the way to anyone struggling with partnership. And, the most valuable advice about anything often comes from those with successful, lived experience. Though well-intentioned, sometimes those who have won fail to understand exactly what they have done right, while unsuccessful people sometimes lend unexpected insights.

Importantly, remember what you learned right here: though many of the happily married seniors recommended waiting to marry, they themselves married young. There very well may be a hidden truth in that piece of do-as-I-say-not-as-I-do advice. Trust your instincts; you'll know when you know.