Ever looked at a happy older married couple and wondered what their secret is? While no two marriages are the same, research shows that all happy, long-lasting marriages share the same five basic traits: communication, commitment, kindness, acceptance, and love.

1. Communication

A study published by Cornell University found that communication is the number one trait of marriages that last. The researchers surveyed almost 400 Americans 65 years of age or older who had been in a marriage or romantic union for at least 30 years.

The majority of the participants said they believed that most marital problems could be resolved with open communication.

Likewise, many of the participants whose marriages had ended blamed a lack of communication for the breakdown of the relationship. Good communication between couples helps maintain closeness and intimacy.

Couples with long-lasting marriages talk to each other without lying, accusing, blaming, dismissing, and insulting. They do not stonewall each other, become passive-aggressive, or call each other names. The happiest couples aren’t those who are concerned about who is at fault, as they regard themselves as a unit; what affects one half of the couple affects the other, and what is most important to these couples is that the relationship is healthy.

2. Commitment

In the same study published by Cornell University, researchers found that a sense of commitment is a key factor in long-lasting marriages.

Among the elders they surveyed, researchers saw that rather than considering marriage a partnership based on passion, the elders saw marriage as a discipline — something to be respected, even after the honeymoon period has ended.

The elders, researchers concluded, saw marriage as “worth it,” even when that meant having to sacrifice short-term pleasure for something more rewarding later on.

Commitment is the glue that holds your marriage together. In healthy marriages, there are no judgments, guilt trips, or threats of divorce.

Healthy couples take their marriage vows seriously and commit to each other without any conditions. It’s this unwavering commitment that builds the foundation of stability on which good marriages are built. The commitment acts as a steady, strong presence to keep the relationship grounded.

3. Kindness

When it comes to maintaining a good marriage, the old adage is true: “A little kindness goes a long way.” In fact, researchers at the University of Washington created a formula for predicting how long marriage would last, with a whopping 94 percent accuracy.

The key factors affecting the length of a relationship? Kindness and generosity.

While it may seem too simple, just think: aren’t kindness and generosity often the first behaviors encouraged in toddlerhood and reinforced throughout a person’s life?

Applying kindness and generosity to marriages and long-term committed relationships may be a little more complex, but the basic “golden rule” should still be applied.

Consider how you interact with your spouse. Are you genuinely engaged when he or she talks to you about work or other things you may not be interested in? Rather than tuning him or her out, work on how to truly listen to your spouse, even if you find the topic of conversation mundane. Try to apply kindness to every interaction you have with your spouse.

4. Acceptance

People in happy marriages accept their own faults as well as those of their partners. They know that no one is perfect, so they take their partner for who they are.

People in unhappy marriages, on the other hand, only see fault in their partners — and, in some cases, they even project their own faults onto their spouse.

This is a way of staying in denial about their own faults while growing increasingly intolerant of their partner’s behaviour.

The key to accepting your partner for who he or she is is to accept yourself for who you are. Whether you snore too loudly, talk too much, overeat, or have a different sex drive than your spouse, know that these aren’t faults; your partner chose you, despite your perceived shortcomings, and he or she deserves the same unconditional acceptance from you.

5. Love

It should go without saying that a loving couple is a happy couple. This is not to say that everyone has to be “in love” with their spouse. Falling “in love” is more of an infatuation than being in a healthy, mature relationship. It’s a fantasy, an idealized version of love that usually doesn’t last.

Healthy, mature love is something that needs time in order to develop, along with the traits listed above: communication, commitment, kindness, and acceptance. This isn’t to say that a loving marriage can’t be passionate; on the contrary, passion is what vitalizes the relationship.

When a couple is passionate, they communicate honestly, resolve conflicts easily, and commit to keep their relationship intimate and alive.