Kids inherit intelligence from their mothers and their dad’s genes make no difference, according to science.
Scientists have long known that intelligence genes are carried on the X chromosome – of which women have two – whereas men have just one. That means a mother is more likely to transmit intellect.
So, good news for those of you with clever-cloggs mothers and dads with an IQ deficit, according to research published in Psychology Spot.
Researchers in Glasgow interviewed nearly thirteen thousand 14 to 22-year-old participants annually from 1994 and found that the best predictor of intelligence was the IQ of the mother.
But here’s where things get a little complex. The evidence has been corroborated in mice studies, which investigated a type of ‘conditioned’ gene that is only activated if they come from the mother or the father.
Cleverness is believed to be one of these conditioned genes that is exclusively influenced by the mother.
Researchers found that genetically modified mice with more maternal genes developed bigger brains and smaller bodies, but the modified mice with more paternal genes developed smaller brains and bigger bodies.
Furthermore, exclusively female cells were found in the cerebral cortex – which controls the most advanced cognitive reasoning, such as language and planning.
Comparatively, no female cells – only male – were found in the lymbic system which controls sex functions, as well as food and aggression.
While this research may compound the importance of specific hereditary traits in mothers and fathers, the influence of nurture rather than nature is still significant.
So, if you think you’re not the smartest cookie in class, don’t blame it on your dad’s genes.
Meanwhile there’s good news for older siblings across the world; your irritating younger brothers and sisters may have youth on their side but you’ve got brains.
According to economists from the University of Edinburgh eldest siblings tends to score higher on IQ tests than their brothers and sisters from as early an age as one.
The scientists behind the research believe that the difference could be that first borns receive more mental stimulation from their parents than their siblings in their early weeks.
Researchers believe that they may have explained the ‘birth-order effect’ which sees older siblings do better in later life than their younger brothers and sisters.
To get to the bottom of this mystery scientists observed 5,000 children from pre-birth until they were 14 on their family background and economic conditions, and they were also assessed every two years on reading and picture vocabulary.
Researchers then applied statistical techniques to analyse how the behaviour of parents, such as smoking and drinking during pregnancy, related to their child’s IQ score.
They discovered mothers tend to take higher risks with later born children than their first and also offered less mental stimulation to younger siblings while also taking part in fewer activities such as reading, crafts and playing musical instruments.
Dr Ana Nuevo-Chiquero from the University of Edinburgh’s School of Economics believes the results suggest a change in parental behaviour are responsible.
Our results suggest that broad shifts in parental behaviour are a plausible explanation for the observed birth order differences in education and labour market outcomes.
So if you feel your eldest brother or sister is doing better in life you may have to look to your parents for the answer why…