In December of last year, a university study revealed the hard-wired differences between the male and female brain. But what of the physical, structural differences?
A study from the University of Cambridge published this week answered these questions. As it turns out, men really do have bigger brains.
“For the first time we can look across the vast literature and confirm that brain size and structure are different in males and females," PhD student Amber Ruigrok said in a statement. "We should no longer ignore sex in neuroscience research, especially when investigating psychiatric conditions that are more prevalent in either males or females.”
A review of previous research on brains revealed the structural differences between male and female brains. (Image source: Ruigrok et. al)
A review of published research from 1990 and 2013 involving people from birth to 80 years old, showed the total brain volume of males was 8 to 13 percent larger than that of females. Here's more of a breakdown of where the volume was different between the sexes, according to the university's news release:
On average, males had larger absolute volumes than females in the intracranial space (12%; >14,000 brains), total brain (11%; 2,523 brains), cerebrum (10%; 1,851 brains), grey matter (9%; 7,934 brains), white matter (13%; 7,515 brains), regions filled with cerebrospinal fluid (11.5%; 4,484 brains), and cerebellum (9%; 1,842 brains).
Now, just where the difference in this volume occurred in male and female brains was especially interesting to scientists. Males had higher volumes in some areas while females had higher volumes in others, for example in the limbic system.
Professor John Suckling explained that the limbic system is often associated with psychiatric conditions with what he called "biased sex ratios," noting autism, schizophreni and depression as examples.
"This new study may therefore help us understand not just typical sex differences but also sex-linked psychiatric conditions," Suckling said in a statement. "It is important to note that we only investigated sex differences in brain structure, so we cannot infer anything about how this relates to behaviour or brain function. Integrating across different levels will be an important goal for future research.”
Though the study had a large sample size, reviewing 126 articles pertaining to the topic, Dr. Meng-Chuan Lai said that most subjects were 18 years or older, leaving room for more research on brain development between the sexes during formative years.
The research was published in the journal.
Featured image via Ruigrok et al./University of Cambridge.
(H/T: Daily Mail)