While children may get their looks from both parents or one or the other, researchers say that when it comes to their brains, children get their smarts from their mother.

According to studies, children are born with conditioned genes that work different ways based on which parent they get them from. Genes for intelligence are found on the X chromosome, and since women carry two of these genes, children are twice as likely to get their intelligence from their mothers.

The same study explains that even if the dad does pass intelligence genes to their child through his one X chromosome, it won’t activate. Intelligence genes only work if they come from a child’s mother.

So does that mean if dad is a genius, his children can’t get that intelligence? Although your dad’s brilliance may not be active in you, if you are a female child, and you carry his inactive intelligence genes, you could at least pass those down to your own children.

Studies done in 1994 in the United States did interviews of mothers and their children between the ages of 14 and 22. Some 12,686 youth were asked questions about IQ, race, socio-economic status, and education. It was discovered that the best predictor of intelligence was the mother’s IQ.

However, keep in mind that a high IQ will do nothing without proper stimulation. Every child needs to be faced with new challenges. So although a father may not pass the genes of intelligence on to their children, they can still help nurture their child’s intelligence.