When talking to singles about mate selection, I always try to take great care not to alarm them. Unfortunately, the raw facts about choosing someone to live with and love well for a lifetime can be daunting. It is especially hard to share this with a confident young person who believes they already have all the necessary skills to make a quick assessment about who is worth their dating efforts and who isn’t.

If you’ll spend a moment and follow me through the following exercise, I think you will learn two important lessons. First, why we think certain people are right for us, and second, why we are so often wrong.

I want you to imagine that you’re in a room right now with 25 persons of the opposite sex—all your age, all single, all available.

What I want you to do in this exercise is imagine that you meet each of these 25 persons and that you spend three minutes with each of them. At the end of the 75 minutes, three minutes for each of the 25, I’m going to come into the room. I’m going to take you over to a corner and ask: "Are there any of these 25 persons with whom you would like to have further involvement?"

On the basis of our research and a lot of experience utilizing this exercise, I pretty much know what you’re going to say. You’re going to give me the names or the numbers of three to five of these people and I’m going to say the same thing that I say every time this happens. You’re kidding! In just three minutes per person, you were able to eliminate 20 to 22 of these single persons your age, all available? How did you do that?

You’re going to fumble around inside your head for the process you used to accomplish this. Most people don’t have a very good idea. I know; I’ve asked them. They don’t have a very good idea for what they did to determine whether or not they want to have further involvement with someone, or put another way, whether they’re attracted to a particular person. But here’s what I think goes on.

You have a huge computer that you carry on your shoulders; a computer that has 2 billion megabytes of capacity. And I believe that you have programmed your computer so that you know pretty much what you want in that person with whom you will spend the rest of your life. When you come up to a given person and meet them and talk with them, you get a sense of where they are on a number of dimensions that relate to the dimensions you have in your mind.

Your brain goes about the task of comparing your wishes and what you actually encounter. Then, your brain concludes whether it thinks this person would be a good match for you over the long term.

When you brain is processing all this data, it has a lot to consider. You’ve already felt her hand. You’ve looked into her eyes. You’ve seen her face. You’ve listened to her voice. You know what her mouth looks like. You’ve heard how she frames her thoughts. You’ve noticed whether she relates to your situation or not. And you’ve compared all this with the ideals you have in your head - in your brain. And your brain already can give you a prediction as to whether or not this person would be a good partner for you over the long years of your involvement with her.