>> - Intelligence peaked among those who were born in 70's and has been in slight decline last 18 years. Similar results can be seen in other developed countrie

>> - Intelligence peaked among those who were born in 70's and has been in slight decline last 18 years. Similar results can be seen in other developed countries. I always wonder when people post these numbers about IQ going up and down over time, what scales are we talking about here? like is it a difference of like 2 IQ points or is it like a difference of 20? Cause if it's 5 or less I can't imagine it would make any real functional difference to the country.