Even though we tend to accredit Sir Isaac Newton with the discovery of the "laws of attraction", it was actually the ancient Greek Philosopher Plato who first studied these phenomenon.
In addition there were others from the ancient world who already understood about the properties of magnets that showed that "opposites attract" and "likes repel".
Then in the mid 20th century, social scientists revisited Plato's law of attraction, that "likes attract", to relationships noting that, for example, people tend to marry based on similarities of such factors as age, religion, socio-economic status, and education.
In the 1950s, in opposition to this view, there was a new movement that advocating the "opposites attract" theory, arguing that people are attracted to those whose personality conversely matches his or her own.
What is the truth?
My view is that maybe both of these views are correct. If, as you meet someone for the first time, you pass the "first impressions" test, you enter the second phase of assessment as a potential love partner. Your potential lover is already subconsciously making judgements about you and your potential as you are about them.
For there to be a point of connection, and after all you are in the same place at the same time for a reason, there will need to be something in common between you. Our subconscious minds are finely tuned to know that the person who has now become the focus of our attention shares similar values and beliefs to us. Nothing builds relationship quicker than a belief that this person believes in, and likes, the same things we do.
Really who wants a relationship with someone who doesn't encourage us to grow emotionally or intellectually?
And besides that, who will make up for what it is we lack? Who will manage the finances if we can't? Who will organise our social engagements and who will pick up after us if we can't do it for ourselves?
So as well as looking for similarities we also look for and need there to be differences to keep some excitement in our relationships.
What differences would we be looking for?
We are not just looking for any differences - we are looking for differences that we find interesting and that will enhance our lives.
But of course living with someone who is in any way different is going to be fraught with danger and potential conflict.
On the positive side there is also the potential to learn things about ourselves that we did not know before and to learn new skills for living that we may not have considered possible.
So rather than two halves making a whole the two people in the couple now have an opportunity to become whole in their own right. What this means in the long term is that the couple are together because they choose to be together not because they need to have a partner to do things for them that they are not able to do themselves.
And as we open ourselves to the learning that is possible from being in a relationship we then naturally also start to become more like each other.
While it may be the differences that will attract us to each other it will be the similarities that will ensure that our relationship makes it for the long term.