Reverberating circuits in the nervous system are bundles of nerves that return their signals to the original source, creating a positively reinforced structure. While this connecting loop happens among certain neurons within our bodies, there is increasing evidence that this type of circuitry can occur between two individuals who are attracted to one another. These reverberating circuits seem to jump across the space between two people. How this works can best be understood by example: If there are two musical instruments near each other, say a piano and guitar, striking an “E” note on the piano will cause the “E” note on the guitar to vibrate as well. The sound waves set up a reverberating circuit to the tone that causes the second instrument to reverberate together harmonically with the first.

It makes sense that sound waves can carry tones across the space between instruments, but how can it work between people? The truth is that we are not really sure just how this system operates, but we have some ideas and we do know that it works and may even be instrumental in how people are attracted to one another.

Though we do not quite know how, we do know that being in the presence of someone we are attracted to triggers chemical reactions in our bodies. Some of the reactions are hormonal and some impact our brain via neurotransmitters – the chemicals that cause the brain to respond to stimuli. These neurotransmitters include dopamine, serotonin, vasopressin and oxytocin. These chemicals cause us to feel excitement – happy and emotionally bonded with others. The key to the triggering of the neurotransmitters release in our own brains is that we feel certain camaraderie with the other person. Much like playing the same musical notes, people we are attracted to are similar to ourselves. The old adage that opposites attract is simply untrue when it comes to friendship and relationships. We have more in common in terms of our basic personalities with those we are attracted to than with people with whom we do not feel a connection. In fact, if we attempt to force a connection with someone who is too dissimilar, we may be creating a disharmony in ourselves.

Psychologists have found that personality can be categorized according to what has come to be known as the Big Five Factors of personality. Each of the following five factors is scored along a continuum from low to high, and can usefully describe every person:

• Openness to new experiences, which comprise a measure of creativity and willingness to meet new challenges

• Conscientiousness, scored according to how devoted a person is to the tasks they undertake
• Extraversion or introversion, how sociable a person is
• Agreeableness or how easygoing each individual is
• Neuroticism, which is based on how comfortable an individual will be in stressful situations.

Scores can be plotted to create a profile that indicates how everyone’s personality functions. Perhaps surprisingly, people who are attracted to one another have very similar profiles. This attraction is stronger among one’s closest friends, more so than with friends or acquaintances who are somewhat distant. In my own research, I’ve found that those in the happiest and most stable marriages are couples who share a profile that ranges from 60–80% comparable. You simply cannot have too little in common to be easily happy together but you also cannot be exactly the same to be happy together, as that may become just a bit too boring. This does not mean that individuals cannot be happily married if their profiles are below 60% congruence. What it may mean, however, is that a couple with less in common may have to learn to work harder to understand one another and learn to accommodate more to each other.

How does one know if he/she has the 60–80% personality profile compatibility? It is possible to test for it using personality measures, but there is a more natural way. If you take the time to really get to know yourself and how you relate to the other person, you are increasing the odds of getting to see how comparable and compatible you are with one another. If you feel very comfortable and have the sense that each of you can anticipate the other’s thoughts and actions, if you tend to be creative or adventurous to the same degree and share similar life goals and hobbies, odds are that you have a lot in common. If you feel like you are forcing activities or that you think differently than the other person about a variety of things, then perhaps you do not have enough in common. Remember though, too much in common, just like too little in common, may not work. Research supports the notion that by using this approach, you may very well increase the odds of finding the most harmonious relations in both friends and a marriage mate.

Dr Michael J. Salamon, a Fellow of the American Psychological Association, is the founder and director of ADC Psychological Services in Hewlett, New York. He is the author of numerous articles and several psychological tests and books. Among his most recent texts is “Every Pot Has a Cover: A Proven System for Finding, Keeping and Enhancing the Ideal Relationship.”