Since researchers began studying the differences between male and female brains, there has been much focus on whether the sexes are "wired" differently. Now, a new study seems to indicate that men and women are in fact wired in opposite ways. University of Pennsylvania researchers scanned the brains of nearly 1,000 men, women, boys, and girls — the largest study of its kind — and generated "connectome maps" based on their findings. The scientists discovered that men's brains are wired from front to back, whereas women's brains are wired from in a crossing pattern from left to right.

These differences support the widely held notion that men are better at completing one specific task or spatial problems, while women are adept at multitasking and communication. Researchers maintain that the findings uphold why men seem to be better at navigation, while women are more skilled at face memorization. (These changes, by the way, only occur after puberty hits.)

But some are not so convinced. "We know that there is no such thing as 'hard wiring' when it comes to brain connections," says University of Oxford professor Heidi Johansen-Berg. "Connections can change throughout life, in response to experience and learning."

So are there actually physical differences between male and female brains, or are our brains shaped by old gender stereotyping as we grow up? Let's take a (somewhat critical) look at what science has proven — or debunked — about our noggins.

Fact: Male brains are bigger

Yes, it's true. Your ex-boyfriend's brain is probably about eight percent larger than yours. But as you used to tell him, size isn't everything. The key seems to be the size of the hippocampus in the brain. For men, a larger hippocampus indicates greater intelligence. But in a women, a smaller hippocampus leads to more efficient learning.

Myth: Women have more brain cells than men

Well, not exactly. There are conflicting reports. Back in 1995, noted researcher Sandra Witelson counted brain cells, and she discovered that women have about 11 percent more nerve cells than men in the areas used for processing language and speech tones. Witelson also said that since the brain's corpus callosum is larger in women, that may explain why girls tend to develop language skills before boys. But a Danish study shows that "the average numbers of neocortical neurons were 19 billion in female brains and 23 billion in male brains." A Stuff You Should Know podcast adds another layer: "Men have about 6 1/2 times more gray matter, which is neurons than women do, but women have about ten times more white matter, which is the connections between those neurons, than men do."

Fact: Female brains are more prone to chronic stress

Witelson also found that male and female brains respond differently toward stress. She says that when men experience stress, the male hippocampus learns from the situation. The hippocampus, which is the core of learning and memory, "sprouts more synapses and dendrites" during that time. But these connections are muted during stressful times for females. Well, that sucks.

Myth: Women aren't as good at science and math as men

Well, this one is complete BS. In fact, girls tend to perform better than boys in all school subjects. However, boys tend to do better on tests that center on non-school subjects. In more gender-equal countries, the difference is nearly negligible. In less affluent countries, the gender divide is quite pronounced. After all, "being poor is not good for anyone's cognitive development," as psychology professor Diana Halpern says.