
X Chromosome Link Theory:
- Women are more likely to transmit intelligence genes to their children because they are carried on the X chromosome and women have two of these, while men only have one.
- The X chromosome carries a significant number of genes related to cognition.
- Since women have two X chromosomes and men have one, it’s theoretically possible that mothers might contribute more intelligence-related genes.
- But: This does not mean intelligence comes only or mostly from the mother.
Genomic Imprinting Studies (Glasgow, 1994):
- Early mouse studies at the Medical Research Council (MRC) in Glasgow suggested that certain “conditioned genes” (imprinted genes) inherited from the mother or father affect brain development differently.
- These imprinted genes can be “switched off” depending on which parent they come from.
- However, this does not prove that intelligence comes only from mothers — it’s about gene expression patterns, not full cognitive inheritance.
University of Washington (2006):
- A 2006 study explored maternal influence on brain development using gene-tracking in mice.
- But again, these were animal studies, not direct human evidence.
- The study did not conclude that intelligence only comes from mothers.
Cambridge 2024:
- As of July 2025, there is no confirmed or published major study from Cambridge University in 2024 that definitively supports this exact claim.
- It’s possible the name is being used in memes or misattributed.
BUT GENES AREN’T THE FULL STORY
It’s important to note that genetics accounts for only 40-60% of intelligence. The rest comes down to environment, stimulation, education, and emotional support areas where both parents and caregivers play critical roles. “A child’s potential is determined by genes, but how far they go depends on the environment they grow up in,
NATURE MEETS NURTURE
Interestingly, mothers often end up playing a more central role not just genetically, but environmentally as well. Numerous psychological studies show that a secure emotional bond
DOES BREASTFEEDING MAKE A CHILD INTELLIGENT?
Breastfeeding may have a small positive effect on intelligence in children, but this effect largely disappears when you adjust for factors like the mother’s IQ, education, and socio-economic status.
MATERNAL IQ AS A STRONG PREDICTOR
A BMJ study (2006) of over 5,400 children found that maternal IQ was the strongest predictor of a child’s IQ. Once maternal IQ was factored in, other variables like breastfeeding or socio-economic status had little impact on cognitive outcomes. Scientific evidence strongly supports that maternal genes, especially those on the X chromosome, have a disproportionately larger role in determining a child’s intelligence but environment and parenting still matter greatly.
While both parents matter, science says intelligence is mostly a mom thing. But don’t worry, dads, you still get credit for the hairline.
CONCLUSION: FALSE / MISLEADING CLAIM
Aspect | Verdict |
“Only mothers pass on intelligence” | False |
“Some genes related to cognition are on the X chromosome” | True |
“Maternal genes may affect brain development in certain ways” | Partially True |
“Supported by University of Washington (2006)” | Misrepresented |
“Supported by Cambridge 2024” | No verified study found |
“Based on Glasgow 1994 mouse study” | But exaggerated and misapplied to humans |
STUDY ORIGIN — ALL ANIMAL-BASED
Study / Claim | Subject | Main Focus | Human Evidence? |
Glasgow, 1994 (Medical Research Council) | Mice | Genomic imprinting and brain development — certain maternal genes affect brain tissue while paternal genes affect reproductive organs | No human replication |
University of Washington, 2006 | Mice | Brain development patterns depending on parent-origin genes | Animal model only |
“X chromosome intelligence” theory | Genetic theory (no specific single study) | Many cognition-related genes located on the X chromosome — women pass one X, men pass X only to daughters | Oversimplified in humans |
Cambridge 2024 | No traceable study | Often cited online, but no verified paper or result exists | Most likely fictional or misattributed |
WHAT DOES THE BROADER SCIENCE SAY?
- Intelligence is polygenic: Influenced by many genes from both parents.
- Environmental factors such as nutrition, parenting, education, and social surroundings play a major role.
- Twin studies and large-scale GWAS (Genome-Wide Association Studies) show that both maternal and paternal genes influence intelligence — there’s no exclusive maternal pathway.
SUMMARY
- The claim is a misinterpretation of early genetic imprinting research and X chromosome studies, especially in mice, not humans. Children inherit intelligence from both parents, and genes are only part of the story — environment matters just as much, if not more.