Dear Dr. Harley,

In your August 5, 1996 Q&A column on Honesty and Openness (part 2) you wrote: "One other suggestion: Don't live with each other before you marry. Eight-five percent of those who do end up divorced. Some day I'll write a Q&A column explaining why."

I've been reading the information on your web site and just recently brought home a copy of the emotional needs questionnaire to go over with my (live-in) boyfriend. We have set aside time each week to discuss one question on it at a time. We have just started this so we haven't gotten very far yet. We're looking at this as preventative maintenance so we do not run into problems in the future. We have been together for 2 years but don't feel ready to get married yet. I think these exercises may help us figure out why that is.

So far, just about everything I've seen makes a lot of sense, but now you've got me wondering why you feel people should not live together before being married. Is it 'some day' yet?

E.N.

Dear E.N.,

The number of unmarried couples living together has increased dramatically over the past few decades, and I expect that it will continue to increase. The rationale is simple: "By living together before marriage, we'll know how compatible we are." Presumably, if a couple can get along living in the same apartment before marriage, they will be able to get along with each other after marriage.

It's a tempting argument. After all, a date tends to be artificial. Each person is "up" for the occasion, and they make an effort to have a good time together. But marriage is quite different from dating. In marriage, couples are together when they're "down," too. Wouldn't it make sense for a couple to live together for a while, just to see how they react to each other's "down" times? If they discover that they can't adjust when they live together, they don't have to go through the hassle of a divorce. Besides, isn't it easier to adjust when you don't feel trapped by marriage?

The problem with those arguments is that marriage changes everything. If couples that live together think that after marriage everything will be the same, they don't understand what marriage does to a couple, both positively and negatively.

In my experience and in reports I've read, the chances of a divorce after living together are huge, much higher than for couples who have not lived together prior to marriage. If living together were a test of marital compatibility, the statistics should show opposite results -- couples living together should have stronger marriages. But they don't. They have weaker marriages.

To understand why this is the case, I suggest that you consider why couples who live together don't marry. Ask yourself that very question. Why did you choose to live with your boyfriend instead of marrying him?

The answer is that you were not ready to make that commitment to him yet. First, you wanted to see if you still loved him after you cooked meals together, cleaned the apartment together and slept together. In other words, you wanted to see what married life would be like without the commitment of marriage.

But what you don't seem to realize is that you will never know what married life is like unless you're married. The commitment of marriage adds a dimension to your relationship that puts everything on its ear. Right now, you are testing each other to see if you are compatible. If either of you slips up, the test is over, and you are out the door. Marriage doesn't work that way. Slip-ups don't end the marriage, they just end the love you have for each other.

What, exactly, is the commitment of marriage? It is an agreement that you will take care of each other for life, regardless of life's ups and downs. You will stick it out together through thick and thin. But the commitment of living together isn't like that at all. It is simply a month-to-month rental agreement. As long as you behave yourself and keep me happy, I'll stick around.

Habits are hard to break, and couples that live together before marriage get into the habit of following their month-to-month rental agreement. In fact, they often decide to marry, not because they are willing to make a lifetime commitment to each other, but because the arrangement has worked out so well that they can't imagine breaking their lease, so to speak. They say the words of the marital agreement, but they still have the terms of their rental agreement in mind.

Couples who have not lived together before marriage, on the other hand, have not lived under the terms of the month-to-month rental agreement. They begin their relationship assuming that they are in this thing for life, and all their habits usually reflect that commitment.

The Policy of Joint Agreement, for example, doesn't make much sense for a couple living together prior to marriage. "Never do anything without an enthusiastic agreement between you and your friend," it is thought, would not be a fair test of your compatibility. A better test would be for each of you to do whatever you please, and then see if you still get along.

But a newly married couple makes a deliberate effort to accommodate each other, because they know their relationship will be for life. They want to build compatibility, not test it. So the Policy of Joint Agreement makes all the sense in the world to a couple who has set out to live their lives together.

It's true, that a couple who lives together can follow the Policy of Joint Agreement from the day they move in. They can commit themselves to each other's happiness as if they were married. They can overcome Love Busters that could destroy their love for each other. But couples who live together tend not to do those things because their month-to-month rental agreement does not demand it. They lack motivation to put each other first in their lives because they are testing the relationship. They're not sure they want each other for life, and so they are usually not willing to make the all-out commitment that the Policy of Joint Agreement demands.

When a couple has lived together without the Policy of Joint Agreement, it's very difficult to apply it once they are married. What they usually do is stay the course. They figure that their month-to-month agreement got them that far, so why change it.

Marriage has a very positive effect on a relationship for those who have not lived together, because they tend to follow the Policy of Joint Agreement without having ever heard of it. They know that they will be together for life, so they make an effort to create a compatible lifestyle from day one.

But marriage has a very negative effect on those who have been in the habit of following the month-to-month agreement. The commitment of marriage is seen as the "other guy's" commitment. Those who have lived together prior to marriage feel that their own behavior has passed the test, and any further accommodation should be unnecessary. Worse yet, they think they don't need to be on their best behavior because their spouse can't leave now that they're married.

Habits are hard to break, and those who have lived together develop habits that work only when they're not married. Marriage ruins it all.

Now, I'm not suggesting that you and your boyfriend should avoid marriage, but I'm warning you that unless you break out of the habits that come from a month-to-month rental agreement, your marriage will be a disaster.

Begin by following my Policy of Joint Agreement. It's not impossible to follow when you care for each other's feelings and put them first in your life. You will create a lifestyle that fits you both perfectly, and you'll wonder why you didn't marry each other to begin with.

Living together may prove compatibility for a moment in time, but it provides no evidence for your happiness together over a lifetime. The only way you can have that happiness and compatibility is if you agree to take each other's feelings into account every time you make a decision. And that's what people who marry after not having lived together are highly motivated to do.