The Male and Female Brains: Are They as Different as we Think?
Everyone seems to know that males and females think and act differently. There is a lot of debate about how much the actual structures of the brain differ between the sexes, but there is no denying that humans have been wondering why and how the male and female brains differ. But, while some brain features are more common in one sex than the other, some are typically found in both, most people have a unique mix. So the answer to how male and female brains differ is more complicated than it seems at first.
The Human Brain
The human brain is the central organ of the human central nervous system. The central nervous system, or CNS, is made up of the brain and the spinal cord. It receives input from the sensory organs and sends output to the muscles. The human brain has the same basic structure as other brains in mammals, but is larger in relation to body size than any other brains. The brain is made up of many specialized brain areas that work together:
- The cerebral cortex – the outermost layer of brain cells. Thinking and voluntary movements begin in the cortex. The cerebral cortex also plays a key role in memory, attention, perception, awareness, language, and consciousness.
- The brain stem – connects the spinal cord and the rest of the brain. The brain stem controls basic functions like breathing and sleeping.
- The basal ganglia – a cluster of structures in the center of the brain. The basal ganglia coordinate messages between multiple other brain areas. The basal ganglia also control voluntary motor movements, procedural learning, routine behaviors or “habits” such as teeth grinding, eye movements, and some parts of cognition and emotion.
- The cerebellum is at the base and the back of the brain. The cerebellum is responsible for coordination and balance.
The brain is also divided into several lobes:
- The frontal lobe, obviously located in the front of the brain, is responsible for problem-solving, judgment, and motor function.The frontal lobe also handles and integrates emotional memories with input from the limbic system.
- The parietal lobe is located above the occipital lobe and behind the frontal lobe. The parietal lobe can actually be divided further into two regions, which controls different functions. One region manages sensation and perception and the other manages integrating sensations, primarily processing information from the visual system. The first region integrates the sensory information it receives and forms a single perception, which is then called cognition, or thoughts. The second region constructs a spatial coordinate system to represent the world around us, and basically tells us where our body is.
- The temporal lobe is located below the frontal and parietal lobes, and is separated by the lateral fissure. The temporal lobe is involved in processing sensory input, which is then retained as visual memory, language comprehension, and emotion association.
- The occipital lobe is the smallest lobe, and is located in the very back of the brain. The occipital lobe contains the brain’s visual processing system.
It is well known that boys and girls differ in their emotional development throughout childhood and adolescence, but the timing, patterning and neurobiological parallels of the difference of development remain poorly understood. Studies suggest that sex steroid receptors are distributed throughout the brain and influence neurodevelopment. Estrogen, androgen, and progesterone receptors are all found in the hypothalamus, consistent with its central role in the control of the sexual and reproductive function. Areas that also have receptors are the amygdala, hippocampus, and cerebellum. The chemistry differences explain why boys sometimes need different methods of stress release than girls.
In 1989, the National Institute of Mental Health (NIMH) initiated a large-scale longitudinal study of typical brain development, which to date has acquired data regarding brain development and function from over 1000 children (including twins and siblings) scanned 1-7 times at approximately two-year intervals. This study has provided much of the information we know about the developing brain today. Studies utilizing this data have found that the peak brain size in females occurs around 10.5 years, while the peak occurs around 14.5 years in males.
The other areas most frequently reported as being different are the hippocampus and amygdala, with the larger size or more rapid growth of the hippocampus is typically reported in females, and the amygdala is larger or grows more rapidly in males. The hippocampus controls emotion, memory, and the autonomic nervous system, and the amygdala is responsible for instinctual reactions including fear and aggressive behavior. Because of the larger hippocampus, girls and women tend to input or absorb more sensory and emotive information than males do.
Additionally, the right and left hemispheres of the male and female brains are not set up symmetrically. Females tend to have verbal processing centers on both sides of the brain, while males tend to have verbal processing centers only in the left hemisphere. Girls tend to use more words when discussing or describing all of the details of a specific experience, however, males have more difficulty discussing their feelings, emotions, and senses, especially when having to describe them all together.
Scientists have also noticed that on average, male brains tend to have slightly higher total brain volume than female brains, about 10% more. However, it has not been found to factor into intelligence; in fact, a recent study found no average difference in intelligence, but males were more variable in intelligence than females.
Male brains have been found to utilize nearly seven times more gray matter, while female brains utilize nearly ten times more white matter. The brain’s white matter is the networking grid that connects the brain’s gray matter together. Gray matter makes up the processing centers of the brain. Brain activity has shown different patterns of activation in the presence of equal cognitive performance, which suggests that male and female brains may follow slightly different paths to achieve similar levels of function. This difference between male and female brains is probably why girls tend to transition between tasks more quickly than boys do. Also, in adulthood, females are great multi-taskers, while men excel in highly task-focused projects.
Why It’s Important
The differences between the male and female brain begin when the brain is just developing. But it’s important to remember that all of the differences are only generalized differences in brain functioning and that all of the differences have advantages and disadvantages. Even though popular culture is abundant with supposed examples of intellectual and behavioral differences between the sexes, only a few are supported scientific research, such as higher aggression in men. Sex differences in the brain may even just depend on your family, and the culture you grew up in. Even if male and female brains start out similarly, the differences over time may come around because boys and girls are treated differently, and have different expectations. Your brain is a muscle and can adapt to almost any situation, but it is important to understand gender differences from a neurological perspective, in order to understand different psychological needs, such as stress release and listening skills.
Jantz, GL. Brain Differences Between Genders. Psychology Today. Accessed April 22, 2017 from https://www.psychologytoday.com/blog/hope-relationships/201402/brain-differences-between-genders
Ritchie, Stuart J., et al. “Beyond a bigger brain: Multivariable structural brain imaging and intelligence.” Intelligence 51 (2015): 47-56.