Turns out, a lot.

I grew up in a feminist household in the 1970s and used to think that all humans were basically wired the same way, other than the obvious physical differences. Males were the way they were because they were forced into sports, were given toy guns and trucks to play with, had different expectations set upon them by society. Females were boxed into nurturing roles as children, given dolls, not allowed to be as physical as boys, blah blah.

I realized how wrong I was when my first niece was born. No matter how many trucks and balls her mom gave her to play with, she really just wanted her jumping horse to nurse her other animal toys. The trucks sat idle. She refused to wear her overalls and wanted pink dresses. She was a girly-girl from the get-go.

The main character in my new novel, Love and Biology at the Center of the Universe (NAL, May 2008) is a middle-aged biology teacher, and she understands human nature at this basic biological level, yet she has tamped down her own nature from the time she was a child. It’s only when she’s forced to that she begins the process of understanding her biology as well as her head and her heart. The journey she makes is not unlike the journey we all go on at some point in our lives: the journey to becoming whole, to finally becoming real, as painful as that often is.

I have to admit that, as a middle-aged woman myself (and by the way, still a proud feminist), I also wanted to explore what it means to be a sexual female in our society at an age where we’re no longer considered (and I apologize for this word in advance, but it is the word bandied about in our culture) “fuckable” by society’s standards. Well, that’s just crazy to me. Why the hell not? We’re at an age where we know who we are, we know what we like, and we pretty much know what our partners like. We’re smart and funny and sexy. We’re damn sexy, in fact, and if certain people don’t see that, I guess it’s best to leave them to their high-breasted, smooth-skinned but generationally-challenged fantasies. I don’t mean to sound bitter, because I’m not. I’m frustrated, but it all comes down to biology. Only by understanding it can we make the choice to move beyond it.

Now is an exciting time in neuroscience research; we hear new information daily about how our hardwiring—our brains—and our software—hormones and other brain chemicals—affect our behavior, our skills, our preferences, even our peccadilloes. After lots of study on the topic, I still believe that men and women are more alike than different, but not as alike as some people used to think, when it was assumed women were really just small men but weaker, emotionally and physically. Up until a couple of decades ago, only men were involved in studies on health, brain function, etc. Women were included more recently, in the last couple decades, and a whole new area of neuroscience has opened up: the differences between men’s and women‘s brains, biology, and behavior.

If this topic fascinates you as much as it does me, well then, read on . . .

The differences between the sexes can now be seen on brain scans and MRIs. Even without social conditioning, even without dolls and trucks and dresses and football uniforms, our brains are anatomically different and they’re hardwired differently. Most people who know such things believe this has to do with a couple of things. 1. the evolution of our species over thousands of years, each gender adapting to fulfill their social roles most adeptly. The whole hunter/gatherer thing. And of course, there’s always 2. keeping the species alive, attraction, romance, mating and then keeping the little ones alive so that they can do the same.

It’s a misnomer that men think with one side of the brain and women with the other. It’s more that men have less connective tissue between these two hemispheres, and so tend to use one side or the other, but not both at the same time. Women’s brains have a larger area of connection between the two hemispheres, hence multi-tasking: buttering the toast while doling out Flintstones vitamins while watching the weather report, putting socks on the two-year-old and thinking about what to have for dinner and what to wear to work. Men, in the meantime, are frying the sausage. Or in a work situation, focusing on one problem at a time and not stopping until it’s fixed. Or in a romantic situation, getting frustrated by a conversation with his wife or girlfriend because she is telling him one story, digressing into a few others, while checking her email and balancing her checkbook.

This is also where women’s intuition comes from. Women are able to incorporate factual information and emotional assessment simultaneously, from both sides of the brain. Didn't you always suspect you really did know everything? You do!

Some more brain differences: While men’s brains are larger than women’s, that doesn’t mean they have higher IQs. Really, it doesn’t. Women have more gray matter, which levels the playing field. Women surpass men on verbal and memory tasks. The language center in women’s brains is about 30% larger than men’s. That’s why women, well . . . verbalize so much. The blood flow in women’s brains is 15% higher than men’s, and the nerve cells are packed 11% more densely, making their brains work more efficiently, and seemingly, more busily.

This has led to a new school of thought about why girls tend to do better than boys in school, not because they’re people pleasers or more passive and attentive than boys. Girls are quicker and more articulate from the get-go, just because of way their brains are built. Boys catch up, by the way, but girls get a jump on them.

And why are women’s brains this way? It seems to go back to the Stone Age, when women stayed close to the fire, tended to the children and others who needed caregiving, the elderly, the sick and wounded. They’re the communicators, making sure everything is going the way it should and that everyone and everything is okay. Some things never change. It’s why women’s brains have developed in the way that makes them more able to read faces, to know exactly what someone else is feeling: so she can keep them alive. Hence, empathy. Men are good at assessing a single strong emotion like rage, good for being able to combat enemies, but not so good with the finer nuances. Women can almost always tell when something is “wrong” with someone they love, a parent or grandparent or child, even when there are no outward signs. They are attuned to many nonverbal clues that men aren’t.

Men and women solve problems very differently, but they solve them nonetheless. Even gossip, thought of as female, has a purpose—to get the emotional lay of the land, to set behavioral standards and guidelines in the family or community, to communicate these. It’s not just frivolity.

The male brain is filled with more white matter, long neuron fibers that communicate better with the more distant regions of the brain responsible for real world responsiveness, like vision and motor coordination, help block the dispersal of information and enhance focus on a particular task. If your dog is hit by a car, who’s going to be able to focus the next day at work, you or your spouse? Men can zero in on a task to the exclusion of everything else. It’s why more boys and men play video games for hours on end, and it’s why they often do more technical jobs that require a lot of singular focus. It’s why they seem more stoical when something bad happens. It’s not that they’re not sad. It’s that they can compartmentalize the problem, and feel sad about it at a given time, then let it go. Or never even go to that compartment in some cases. Men are more adapted to avoiding unpleasant emotion so they can focus on the task at hand.

We all know men’s spatial reasoning skills are superior to women’s. Parking the car, packing the van. It’s brain architecture. They know what an object looks like from any angle, how long something is, how wide. They also have an inner compass that most women do not, dead reckoning. Why? Because in early times they traveled farther afield to hunt, to explore, to scout, and had to be able to find their way back. Women used landmarks, then as now, to get the short distance from where they foraged back to the fire. Over the millennia, men’s and women’s brains evolved different neural pathways for getting around. Solving the same problems, but differently. We can both still find our way, we just do it differently. A man isn’t going to think of the place he has to go as being the blue house just past the Episcopal church. He’s going to think of it as being two miles north of Broadway on the southwest corner of 12^th and Pine.

But really, the most important area of difference in brain biology, for writers anyway, is the way men and women deal with emotion. Here’s the question every man wants the answer to:

WHY DO WOMEN GET SO EMOTIONAL?

It has to do with the way the brain, or rather the emotional portion—the amygdala—processes memory in each gender. When men in a study were shown graphically violent films, the right half of their amygdalas fired up—the area more in tune with the outside world, vision, and motor coordination. This is why men are more likely to want to take action. Women process these same graphic images through the left side, where sensory information is translated into emotional experience, and also to the hypothalamus, the master regulator of the basic body functions. This is why when women are upset by something, they get upset stomachs, can’t sleep or eat.

STRESS

Women produce more of the hormone cortisol during times of stress, known as the stress hormone, so they actually feel more stressed than men. Other women pick up these cues and help each other. The hormone oxytocin motivates women to make and preserve connections with other people. This was needed in the past to help keep the offspring alive, the most important job on the planet at that time. Women recruit help. Women ask for directions.

Under stress, the right side of men’s amygdalas kick in to fight or flight rather than emotion. The way they will solve the problem, if they choose to fight, is to focus on the problem, work on it until a solution is reached, then move on. They may not remember much about it later, because it’s not important, as it is for women, to remember.

MEMORY

All of these things, plus estrogen, contribute to women’s ability to imprint memory in excruciating detail. The usefulness of this in Stone Age times was that women needed to remember dangerous things and situations, like which plants were poisonous, and which watering holes were frequented by large carnivores. Men, when women tell you exactly what you said eighteen years ago during a fight on your third anniversary after dinner, I’m sorry, but you should probably believe them.

ANGER

The area of the brain responsible for keeping impulsivity and aggression in check, the frontal cortex, is larger in women than in men. This area helps control the amygdala, behind it, the primitive part of the brain that sends fight or flight signals to start adrenaline pumping through the body. Women have a bigger “braking” system, if you will, and will try to reason and defuse. Men take action, becoming angrier quicker.

LOVE & ROMANCE

At a biological level, women search for partners who can provide emotional support and real-world security—good co-parents and providers. At the same biological level, the male’s job is to impregnate a female possessing good genes, take care of her during her pregnancy, and stick around until his offspring is old enough to thrive. He will impregnate as many different women as possible to ensure his genes are passed on. Some scientists believe that “taking care of the offspring until they’re viable human beings” is what lies beneath the old “seven year itch” theory, but any mature adult knows this is not any kind of excuse for modern day behavior. Our brains are much more complex now, and the world no longer needs populating.

Still, study after study shows that women favor men with square jaws, prominent cheekbones, and big smiles because these features, at a cellular level, indicate sexual maturity and high levels of testosterone. He will be able to make her pregnant and be aggressive enough to fight off predators and danger.

Men, at a biological level, search for partners who are young and healthy enough to reproduce and continue their lineage, spread their seed. Think about the stereotypical features men seem to like: large breasts are good for feeding babies. Curvy hips, good for carrying babies and giving birth. Long shiny hair, clear skin, long fingernails all indicate good health. A youthful face indicates someone young enough to bear many children.

BELIEVE ME, I'm not making excuses for anybody, but as a writer, I must seek first to understand, first to get inside of the head of the opposite gender, from a biological viewpoint, and then to write real world people with all of their complexities and differences. Writers can’t rely on the shorthand of sex stereotypes. Well, they shouldn’t. I promise to always try not to.

And as much as my feminist self hates to admit it, I’m not as good as determining if the leftover spaghetti will fit into a certain Tupperware container as my husband is. But I can tell him when he’s just hurt someone’s feelings and doesn’t realize it.

In two years we’ll complete our third seven-year itch. Sometimes, oftentimes, love wins over biology.