Big brain? You can thank mom for that.
According to researchers, the mother is responsible for the intelligence genes passed on to kids.
Psychology Spot explains that intelligence genes are found on X chromosomes, making women more likely than men to pass them on.
Furthermore, researchers believe intelligence may be a "conditioned gene." Conditioned genes behave differently based on where they come from -- for example, some passed down genes are only activated if they come from the mother. Others are only activated if they come from the father.
A study involving rat embryos indicated that intelligence may be a conditioned gene that is only activated when it comes from the mother.
Another study furthered the suspicion that smarts come from mom -- a study out of Scotland interviewed 12,686 young people and found the best predictor of intelligence was the IQ of the participant's mother. Ultimately, the ratio of the participants' intelligence varied an average of 15 points from that of their mothers.
Of course, genes are not the only predictor of intelligence. Other studies found positive physical and emotional contact from the mother played an important role in development, among a variety of other environmental factors.
Cox Media Group