Cambridge researchers found that sex differences in brain structure exist from birth, with males having more white matter and females more grey matter, highlighting early neurodiversity.
Research from the Autism Research Centre at the University of Cambridge has found that sex differences in brain structure are present from birth.
On average, male infants have larger overall brain volumes than female infants. However, when accounting for total brain size, female infants tend to have significantly more grey matter, while male infants have significantly more white matter.
Grey matter consists of neuron cell bodies and dendrites, playing a key role in processing and interpreting information related to sensation, perception, learning, speech, and cognition. In contrast, white matter is composed of axons—long nerve fibers that connect neurons across different brain regions, enabling communication throughout the brain.
Yumnah Khan, a PhD student at the Autism Research Centre, who led the study, said: “Our study settles an age-old question of whether male and female brains differ at birth. We know there are differences in the brains of older children and adults, but our findings show that they are already present in the earliest days of life.
“Because these sex differences are evident so soon after birth, they might in part reflect biological sex differences during prenatal brain development, which then interact with environmental experiences over time to shape further sex differences in the brain.”
Overcoming Past Research Limitations
One problem that has plagued past research in this area is sample size. The Cambridge team tackled this by analyzing data from the Developing Human Connectome Project, where infants receive an MRI brain scan soon after birth. Having over 500 newborn babies in the study means that, statistically, the sample is ideal for detecting sex differences if they are present.
A second problem is whether any observed sex differences could be due to other factors, such as differences in body size. The Cambridge team found that, on average, male infants had significantly larger brain volumes than did females, and this was true even after sex differences in birth weight were taken into account.
After taking this difference in total brain volume into account, at a regional level, females on average showed larger volumes in grey matter areas related to memory and emotional regulation, while males on average had larger volumes in grey matter areas involved in sensory processing and motor control.
The findings of the study, the largest to date to investigate this question, are published in the journal Biology of Sex Differences.
Investigating Underlying Biological Factors
Dr Alex Tsompanidis who supervised the study, said: “This is the largest such study to date, and we took additional factors into account, such as birth weight, to ensure that these differences are specific to the brain and not due to general size differences between the sexes.
“To understand why males and females show differences in their relative grey and white matter volume, we are now studying the conditions of the prenatal environment, using population birth records, as well as in vitro cellular models of the developing brain. This will help us compare the progression of male and female pregnancies and determine if specific biological factors, such as hormones or the placenta, contribute to the differences we see in the brain.”
The researchers stress that the differences between males and females are average differences.
Dr Carrie Allison, Deputy Director of the Autism Research Centre, said: “The differences we see do not apply to all males or all females, but are only seen when you compare groups of males and females together. There is a lot a variation within, and a lot of overlap between, each group.”
Professor Simon Baron-Cohen, Director of the Autism Research Centre, added: “These differences do not imply the brains of males and females are better or worse. It’s just one example of neurodiversity. This research may be helpful in understanding other kinds of neurodiversity, such as the brain in children who are later diagnosed as autistic, since this is diagnosed more often in males.”
Reference: “Sex Differences in Human Brain Structure at Birth” by Yumnah T. Khan, Alex Tsompanidis, Marcin A. Radecki, Lena Dorfschmidt, APEX Consortium, Topun Austin, John Suckling, Carrie Allison, Meng-Chuan Lai, Richard A. I. Bethlehem and Simon Baron-Cohen, 17 October 2024, Biology of Sex Differences.
DOI: 10.1186/s13293-024-00657-5
The research was funded by Cambridge University Development and Research, Trinity College, Cambridge, the Cambridge Trust, and the Simons Foundation Autism Research Initiative.
These results were obtained using data made available from the Developing Human Connectome Project funded by the European Research Council under the European Union’s Seventh Framework Programme (FP/2007-2013) / ERC Grant Agreement no. [319456].
News
Born Different? Cambridge Scientists Uncover Innate Sex Differences in Brains
Cambridge researchers found that sex differences in brain structure exist from birth, with males having more white matter and females more grey matter, highlighting early neurodiversity. Research from the Autism Research Centre at the University [...]
New study shows risk factors for dementia – virus causes deposits in the brain
Research into the causes of Alzheimer's is not yet complete. Now a new study shows that head trauma can activate herpes viruses and promote the disease. Frankfurt am Main – As a neurodegenerative disease, [...]
Are Machines Truly Thinking? Modern AI Systems Have Finally Achieved Turing’s Vision
Modern AI systems have fulfilled Turing’s vision of machines that learn and converse like humans, but challenges remain. A new paper highlights concerns about energy consumption and societal inequality while calling for more robust [...]
The Surprising Link Between Smell, Sound, and Emotions
New research reveals how smell and hearing interact in the brain to drive social behavior, using mouse maternal instincts as a model. Imagine you’re at a dinner party, but you can’t smell the food [...]
Brain cells age at different rates
As our body ages, not only joints, bones and muscles wear out, but also our nervous system. Nerve cells die, are no longer fully replaced, and the brain shrinks. "Aging is the most important risk factor [...]
Long COVID Breakthrough: Spike Proteins Persist in Brain for Years
Researchers have discovered that the SARS-CoV-2 spike protein persists in the brain and skull bone marrow for years after infection, potentially leading to chronic inflammation and neurodegenerative diseases. Researchers from Helmholtz Munich and Ludwig-Maximilians-Universität (LMU) have [...]
Water-Resistant Paper Could Revolutionize Packaging and Replace Plastic
A groundbreaking study showcases the creation of sustainable hydrophobic paper, enhanced by cellulose nanofibres and peptides, presenting a biodegradable alternative to petroleum-based materials, with potential uses in packaging and biomedical devices. Researchers aimed to [...]
NIH Scientists Discover Game-Changing Antibodies Against Malaria
Novel antibodies have the potential to pave the way for the next generation of malaria interventions. Researchers at the National Institutes of Health (NIH) have identified a novel class of antibodies that target a previously unexplored region [...]
Surprising Discovery: What If Some Cancer Genes Are Actually Protecting You?
A surprising discovery reveals that a gene previously thought to accelerate esophageal cancer actually helps protect against it initially. This pivotal study could lead to better prediction and prevention strategies tailored to individual genetic [...]
The Cancer Test That Exposes What Conventional Scans Miss
Researchers at UCLA have unveiled startling findings using PSMA-PET imaging that reveal nearly half of patients diagnosed with high-risk prostate cancer might actually have metastases missed by traditional imaging methods. This revelation could profoundly affect future [...]
Pupil size in sleep reveals how memories are processed
Cornell University researchers have found that the pupil is key to understanding how, and when, the brain forms strong, long-lasting memories. By studying mice equipped with brain electrodes and tiny eye-tracking cameras, the researchers [...]
Stanford’s Vaccine Breakthrough Boosts Flu Protection Like Never Before
Stanford Medicine researchers have developed a new method for influenza vaccination that encourages a robust immune response to all four common flu subtypes, potentially increasing the vaccine’s efficacy. In laboratory tests using human tonsil [...]
Water’s Worst Nightmare: The Rise of Superhydrophobic Materials
New materials with near-perfect water repellency offer potential for self-cleaning surfaces in cars and buildings. Scientists from Karlsruhe Institute of Technology (KIT) and the Indian Institute of Technology Guwahati (IITG) have developed a surface [...]
Japanese dentists test drug to help people with missing teeth regrow new ones
Japanese dentists are testing a groundbreaking drug that could enable people with missing teeth to grow new ones, reducing the need for dentures and implants, AFP recently reported. Katsu Takahashi, head of oral surgery at [...]
An AI system has reached human level on a test for ‘general intelligence’
A new artificial intelligence (AI) model has just achieved human-level results on a test designed to measure "general intelligence." On December 20, OpenAI's o3 system scored 85% on the ARC-AGI benchmark, well above the previous AI best [...]
According to Researchers, Your Breathing Patterns Could Hold the Key to Better Memory
Breathing synchronizes brain waves that support memory consolidation. A new study from Northwestern Medicine reports that, much like a conductor harmonizes various instruments in an orchestra to create a symphony, breathing synchronizes hippocampal brain waves to [...]
