"why the average IQ would be 100 and not 180. Why wouldn't directional selection for IQ have just run this all the way up to the max?" Intelligent people have

"why the average IQ would be 100 and not 180. Why wouldn't directional selection for IQ have just run this all the way up to the max?" Intelligent people have less babies as they tend to plan their lives (http://www.thenakedscientists.com/HTML/questions/question/2304/ http://www.thenakedscientists.com/HTML/questions/question/23...). The good news are that Flynn effect counterweights this effect (at least for now).