We all know the alarming statistics on divorce rates. In the United States, approximately half of marriages end in divorce. In Europe, the percentage is even higher.

But when, exactly, in the long and winding road of marriage is a divorce most likely to occur? We can look to research for an answer. Here are three divorce "inflection points," according to psychological research.

1. The "Early Years" Divorce

Research shows that the first seven years of marriage are when relationships are most vulnerable. Half of all divorces happen within the first seven years of tying the knot.

There are many reasons why this is the case. Sometimes, it's the acknowledgment of an honest mistake—compatibility between two people simply wasn't what they expected it to be.

It could also be the case of realizing that living together, forever, isn't going to work. The two people might have different expectations of shared household responsibilities and personal space and time, which causes their union to crack. This is especially common in cases where partners didn't cohabitate before marriage—or at least didn't cohabitate for enough time to realize that issues might arise.

Another reason why marriages are most likely to end early is that it gives people ample time to reestablish themselves, perhaps remarrying and starting a family with someone else while still young.

Evolutionary psychologists have an interesting take on why early divorces occur—and it has to do, not surprisingly, with what they believe to be marriage's core function: the production of offspring. Here's what evolutionary psychologists Glenn and Carol Weisfeld have to say on the topic:

"Divorce disproportionately occurs early in marriage when there are few, if any, children. The peak in divorce at around four years into marriage may be explained in proximate terms by a waning of infatuation after two or three years into a romantic relationship. This decline in amorousness may be adaptive in allowing dissolution of a marriage that has been barren, and alternatively in allowing couples with a child to divert more emotional investment away from each other and toward their helpless infant. The marriage will then be sustained partly by the parents' attraction to their infant."

2. The "Self-Sufficient Children" Divorce

Another common marriage dissolution point, according to research, occurs when the first child reaches approximately 14 years of age. This is known to be a low point for marital satisfaction, and sometimes results in the partners deciding to call it quits.

Again, from an evolutionary standpoint, the "self-sufficient children" divorce makes a certain degree of sense, as the primary evolutionary goal of the relationship—producing children—has already been accomplished.

3. The "Empty Nest" Divorce

When children leave the house, it opens up a new chapter in a couple's married life. In some cases, this means more time to spend together—which can result in an improvement in marital satisfaction.

On the other hand, not having children in the house makes the idea of divorce that much more feasible. Sociologist I-Fen Lin and her collaborators had this to say about empty nest divorces in a December 2018 paper:

"The absence of resident children removes a potential barrier to divorce. Children are the glue holding some couples together. An empty nest can lay bare the couple's relationship strains or distance that emerges without the buffer of resident children. One study found that an empty nest is related to a higher risk of divorce among the middle-aged."

Naturally, every marriage is different and follows its own time course. If there's one golden rule that can be applied to all marriages, it's that every day a couple stays together makes it that much more likely it will remain that way.

Not sure whether your relationship/marriage is fit to stand the test of time? Take the Marital Satisfaction Scale to learn more.

A similar version of this article can also be found on Forbes.com,here.