A Canadian study performed by a zoologist and two psychologist claims to show that a "the nerves in men's brains [...] may have greater conductivity because they have thicker coatings of myelin," leading to a 4% faster nerve conduction velocity (NCV). This article, in a typical act of journalistic sensationalism, translates this to "Men think 4% faster than women". The study has been getting a lot of negative reaction.

I didn't read the actual report of the study; just the article on it, so I'm getting second hand information, but from my understanding, the scientists did not directly measure the conductivity of the nerves, but rather used electrodes to record how long it takes for an image to be translated into an impulse and sent to the visual cortex. Rather than demonstrating that men "think faster" than women, or even that "men's nerves have a higher NCV than women", to me, this only shows that "men are able to translate an image into an impulse and send it to the visual cortex faster than women", with the "4% higher NCV" merely being a hypothesis to explain why men can perform this translation faster. I'm not saying this is a necessarily a bad hypothesis; after all, the fact that that men have a thicker coat of myelin does certainly sound impressive, but IANA Biologist, so I have no idea how strongly these facts support the hypothesis.

Even assuming that the hypothesis is true, that men do have a higher NCV than women, this might have very negligible affect on "speed of thinking", which itself is a difficult to measure. I'll compare this to trying to measure which CPU is "faster": Intel's of AMD's? One way we measure the relative speeds of the CPUs is to perform "real world benchmarks", which means we use the CPUs to perform tasks that we might before in real life, and see which CPU can finish the task faster. For example, we might ask it to encode six CDs of music into mp3, or tell it to render a single frame from Pixar's latest movie, and time how long the CPUs take to perform each task. Not surprisingly, there are some tasks in which Athlon's CPUs finish earlier and other tasks where Intel is faster. Similarly, we could perform "real world benchmarks" on men and women's brains, perhaps by having them solve crossword puzzles, or put together jigsaws, etc. I have no doubt that there will be some tests for which male brains finish earlier, and other tasks where female brains finish earlier.

The second way of testing CPU speeds is called "synthetic benchmarks", which typically consists of using a program that has no use except to test the speed at which a CPU can perform a very specific operation, for example adding two numbers together. The benchmark might consist of adding two numbers together a billion times, and seeing who finishes first. These tests are called synthetic because "real life applications", like Microsoft Word or FireFox don't behave anything like the way these benchmarks do, and so they aren't an accurate reflection of how fast the CPU will "feel" when you're using it for day to day tasks. They are useful however at testing a particular component of the CPU (is Intel's Arithmetic unit faster than AMDs? Perhaps AMD has a faster memory access, etc.) The biological analogue to synthetic benchmarks is the tests performed in the article. It's (supposedly) measuring the nerve conduction velocity. In this particular synthetic benchmark, it looks like men performed 4% faster than women.

The last way, which is often the most tenuous, is to perform an analysis of CPU itself. Gain access to the blueprints of the CPUs, and you can make statements like "This Intel chip has a bigger instruction cache, so it must be faster than AMD!" or "AMD's has more floating point units, so it can go through its calculations faster than Intel" etc. This is akin to saying "The male brain's nerves have a thicker coat of myelin".

The final point I'm going to draw from this analogy is to compare the brain NCV with CPU clock speed. Again, I'm not a biologist, so I don't know what the hell NCV is exactly, but it sounds like it's the velocity (i.e. speed) at which a brain cell can send a signal to another brain cell (or at least, NCV is directly proportional to the speed a which a brain cell can send a signal to another brain cell). What I do know is that the brain is extremely complex, and no one really knows how it works. In particular, we don't know if sending signals around faster would actually lead to faster thinking. For one thing, the brain seems to have an internal clock, and even if you send signals around faster, actually processing these signals might be limited by how often your internal clock ticks. Furthermore, simply increasing this clock speed might not be enough to make you perform "real world benchmarks" faster. An AMD CPU which can perform 2.2 billion calculations per second completes real world benchmarks about as fast as an Intel CPU which can perform 3.5 billion calculations per second. How is this possible? AMD chips are typically wired more efficiently. (As an aside, the reason AMD doesn't tromp out Intel completely is that Intel can actually produce chips with 3.5 billion calculations per second, whereas AMD's chips tend to overheat and burst into flame when they reach that high). Some people might argue "Why would this apply to the human brain? Aren't we all wired the same way?" And the answer to that is "we don't know, but probably not." In fact, the brain seems to be wired randomly, and the cells "learn" what the wiring is, and adapts. When people, for example, lose the part of the brain that processes vision because of an accident, they can "re-learn" how to see, because other parts of the brain learn how to process vision. No only is the brain wired randomly, but it seems to be able to re-wire itself as needed. In fact, some people believe that re-wiring is the only way that the brain is capable of learning. If this is true, then since we all learned things in different ways, all our brains are wired differently. Some of us might have a more efficient AMD style brain, while some of us might have a higher NCV Intel style brain. Okay, that's the end of the analogy.

Now believe it or not, there are a lot of people out there who comment on news articles before they read the news article (usually, but not always, they'll at least read the headline). As a result, there are a lot of people who are protesting "A Canadian study shows that men think 4% faster than women? Bullshit! Scientists are all idiots. Didn't one of them say that tomatoes cause cancer, and then another one said tomatoes help fight cancer? Which is it Einstein? It's all fucking bullshit!" Whereas if they actually read the article, they'd find out that it was the journalist, and not the scientists, who claimed that men think 4% faster than women. My follows are some choice quotes, names omitted.

Men commit more homicides, rapes, suicides, and general crime than women. Nu? Thinking fast is a benefit to society? I'm not going to bother arguing that she's being overly offensive, and that bringing in rapes and such is off topic. Rather, I'll point out that if "thinking fast" was the main cause of rapes, then given that men only "think faster by 4%" (which is also false, but I'm trying to follow her logic here), then men would probably commit rapes about 4% more often than women. I'm pretty sure in actuality, the male/female rape ratio is a lot higher than 4%.

Less than 400 were investigated in this "study" while at least 1000 people need to be interviewed for it even to be concidered as scientific evidence. And it did not state the conditions that the subjects were tested in or what physical condition they were in all things which have been know to change the results about these things. But what do I know? I'm only a female science major... I hate to use the acronym "LOL", but here it seems appropriate. I wonder where she got 1000 from, and why she believes it should be a hard number at all. As for the conditions, I could see how if the study only tested women at 3AM in the morning, and men at around 4PM, how the results might be skewed somewhat, but I assumed the study was conducted in "good faith", that is to say, the men and women conducted under similar conditions. Anyway, I seriously wonder, being a science major, she learned about that 1000 figure.

Speed also causes people to overlook details; thorough contemplation requires a steady, meticulate pace. This study is very specifically about translating an image to signals in the brain. It provides evidence that if you flash a complex diagram for 500 milliseconds, males will probably have saw more details than women. Given, the study says nothing about ability to concentrate on a picture for long periods of time, so if the diagram were shown, instead of 500 milliseconds, say, 500 minutes, perhaps females would tend to be able to recall more details, but then again, perhaps not. However, there is no reason to believe that men (or people who "think fast") are incapable of looking at an image until they've judged that they have seen enough details for whatever task they are trying to accomplish, and the higher NCV leads one not believe that male brains would have gathered "enough" details sooner than female brains would.

It is important to remember that we are dealing with averages here. That means we cannot say "X female is smarter than X male so this research is invalid." It also means that this research may run counter to our experiences as a whole because those might be biased by the groups with whom we interact. We must instead look at the research and see if the research was done in a valid manner rather than comparing it with our own experiences. Of course, people are more than welcome to try and duplicate and/or provide a counter experiment to obtain new results; however, this should be done in a scientific way. We must also be careful not to draw conclusions that do not have basis in the research. With something like this, it is all to easy to assume that the research is saying something that it isn't. Yay, this person is smart.