Yesterday, I mentioned brain styles and evolution in my post, in the context of romance - do opposites attract, or does like call to like?
The answer is ... yes.
First of all, the brain styles aspect. Most of you are probably familiar with the concept of Left Brain (Logical Brain) and Right Brain (Creative Brain). It's a bit more nuanced than that, but it will do for the purposes of this post. The brain is further divided into Frontal and Basal regions. The Frontal portion of the brain deals with intellectual and abstract thinking. The Basal portion deals with emotional and concrete thinking.
So we end up with four quadrants: Left Frontal (Scientist), Right Frontal (Artist), Left Basal (Administrator) and Right Basal (Counselor). Most people have a preference for one quadrant or two adjacent quadrants. Rarely, people will have a preference for three (leaving a deficiency in the fourth quadrant) or will be whole-brained. That doesn't mean, of course, that you can't work in the other areas, just that you naturally gravitate towards certain kinds of thinking.
(For those of you into Tarot: Swords = Left Frontal. Wands = Right Frontal. Pentacles = Left Basal. Cups = Right Basal.)
If you picture this, it's pretty obvious to see that each quadrant has an opposite. For instance, Left Frontal is the opposite of Right Basal. And the opposites usually drive each bonkers because they have little common ground.
On to the evolutionary aspect. Obviously, each quadrant has its strengths and weaknesses. From an evolutionary standpoint, then, when people are younger and in survival mode, they instinctively seeking out an opposite brain - someone strong where they are weak and vice versa. Together, these people make a whole brain. As a strategy for taking on the world, it's a good one ... but what happens when the problems start fading away and these opposed couples no longer have a common "foe" in life?
Later in life, when finances, career, family, etc are more stable, the brain shifts from seeking survival to seeking companionship. Instead of an opposite brain, it wants a similar brain - someone in the same quadrant or with whom there is overlap.
So opposites attract ... *and* like calls to like. It all depends on where you are in your life (if you buy into the theory, of course).
Do I consider this in my writing? Perhaps not consciously, but as I get older (hush!), I've noticed a shift in pattern in the romances I choose to write. My earlier works featured a lot more pairs that were opposites. Now, I tend to set up characters who - though they may clash over specifics - think more alike. Proof, self-fulfilling prophecy, or coincidence? Who knows ...