First, I believe that this is true because of what I understand about how guys like to be positioned in the world. Men prefer to be on top when it comes to societal hierarchy, and they are conscious of what people think about them, with regards to the relationship between them and their partner. Men have a need to be higher than their partner in several ways, one of them being in intelligence. Women that are smarter than their male partner can possibly make him feel emasculated, and, as a result, make him less likely to stay with her for any extended amount of time. Since time immemorial men have been the head of the family; it is bred into their lives as they grow from adolescence into manhood. To have a women be more intelligent than them would go against every fiber of their being, resulting in low self-esteem and potential arguments in the relationship.
Another reason that I believe Jong’s statement to be true is that I think that smart women dislike being in a long-term relationship with an unintelligent man. Women prefer to be in a relationship with someone that can carry a conversation beyond greetings and small-talk. They would much rather have a partner that either is either equal or near-equal as far as mental capabilities goes. If a woman has a Masters in Political Science she would not enjoy having a date with someone that could only discuss politics as much as an eight year-old; in contrast, a man with the same educational background would not likely have the same objections to having a date with a woman that did not know anything about politics nor even cared at all.
My final