The Flynn Effect is somewhere in the neighborhood of 1/3 IQ point per year. So unless your girlfriend is 120 years younger than your grandmother...
Also the Flynn Effect is observed in similar magnitudes in men and women. IQ_you/IQ_yourgirlfriend is predicted to be the same as IQ_grandpa/IQ_grandma, at least the part of that ratio attributable to the Flynn effect.
He didn't actually mention the Flynn effect in the above post.
This is a thread where people can ask questions that they would ordinarily feel embarrassed for not knowing the answer to. The previous "stupid" questions thread went to over 800 comments in two and a half weeks, so I think it's time for a new one.