The battle of the sexes has been going on for eons. With recent advances in brain scan technology, researchers are finding exciting new evidence to suggest that men and women don't simply appear different, they're actually wired differently, too. Researchers are quick to point out that there is no calculable research to suggest that one gender is more intelligent than another. In IQ tests and such, men and women perform similarly. However, there are some structural differences that may explain why men are generally better at remembering driving directions and women are generally better at remembering emotional events like anniversaries and weddings.

Emotional Processing and the Amygdala

Gray and white matter differ by gender
Gray and white matter differ by gender

On the "Truth About Boys and Girls" segment of NBC Nightly News, researchers indicate that men and women differ in their recall of emotional events. When discussing their wedding, Dick and Madeline Neuman exhibited some clear differences. Dick remembered the basic events, picking her up, going through the ceremony, having a reception and taking off. However, Madeline's memory was much more detailed, they were married really early in the morning, their car was full of balloons and her veil caught on fire at the reception. In fact, during brain scans where participants are shown pictures carefully chosen to elicit an emotional response, men tend to store the information on the right side of the amygdala (where they can separate emotions from details), whereas women store them on the left side of the amygdala (where they can retrieve this information much more easily). The study found that there were some similarities between the two sexes. For instance, when shown a very frightening, aggressive or intense image, both sexes showed heightened brain activity on the left side of the brain. However, when later asked to recall that image, men were more likely to remember if their right brain (the "creative" side) was activated and women were more likely to remember if their left brain (the "logical" side) was activated.

Gray Matter vs White Matter

Brain activity also differs between men and women
Brain activity also differs between men and women

The human brain is comprised of both gray matter, which represents information processing centers, and white matter, which works to network these processing centers. In a new study, UC-Irvine psychology Richard Haier found that men have 6.5 times the amount of gray matter than women. However, women have almost 10 times the amount of white matter. "These findings suggest that human evolution has created two different types of brains designed for equally intelligent behavior," said Dr. Haier. He added that this also explains why men are generally better at tasks involving localized processing like mathematics, whereas women generally excel at integrating and assimilating tasks like language.

Where Men Excel: Spatial Locations

In a 2006 study at the Institute of Evolutionary Biology in Edinburgh, researchers found that men were better than women at remembering the locations of objects, accessing both visual and location information. It seemed that the women relied on landmark or feature cues, while men accessed more abstract cues like geometrical properties of the environment and compass directions. Another study by psychologists Agneta Herlitz and Jenny Rehnman in Stockholm, Sweden confirmed that men were more likely to "find their way out of the woods" than women. The men outperformed women in visuo-spatial processing, they concluded.

In July 2008, researchers at the Institute of Psychiatry, King's College London posited that there males use different genes from females when creating long-term memories. This may account for why men are better at remembering tactical memories like trivia and travel directions. Furthermore, men have a larger parietal cortex, which explains why they are generally better with space perception, balance and recognition memory.

Where Women Excel

Psychologists Agneta Herlitz and Jenny Rehnman in Stockholm, Sweden found that women excelled at episodic memory, recalling words, objects, scents and faces better than men. Verbal recall is usually better in women because of their enlarged hippocampus region, researchers conclude. Memories that are verbal in nature, whether spoken, heard or written, are easily processed by women.

They were also better at finding the location of car keys, which requires both verbal and visuospatial processing. Since a girl's corpus callosum (the bridge between different hemispheres of the brain) is up to 25 percent larger than a boy's, women are better able to recall these memories involving various storage centers in the brain. They also have stronger neural connectors in their temporal lobes, which enables them to listen better, pick up on non-verbal communication cues (like tone of voice) and recall sensual details better than men.

A Harvard Medical School study concluded that parts of the frontal lobe (the decision making center) and limbic cortex (which regulates emotion) are larger in women, compared to their male peers. This may also account for why women remember emotionally-charged incidents--weddings, birthdays, accidents--in more vivid detail than men.

As We Age

In 2008, researchers from the Mayo Clinic in Rochester, Minnesota found that men were 1.6 times as likely as women to have cognitive impairments like dementia and Alzheimer's as they age. This also rang true for milder impairments. "A person with mild cognitive impairment might have problems with memory, making decisions, or problem solving, or problems with language, like finding a [right] word," explained Rosebud Roberts, MD, associate professor of epidemiology.