The traditional view is similar to IQ as an empty glass. You can fill it up to the top, but once you're there, you've maxed out on IQ itself. Different people have differently sized glasses, and there are many things that clearly affect the rate or amount of fill, just as there are many things that affect height. However, there are few things that indicate that they are increasing the potential IQ.
Losing a tire in my car won't make me lose any horsepower, but it's not going to be the same ride.
is that each individual has a "reaction surface," a range of possible behavioral responses genetically endowed for that individual depending on what environmental influences that individual encounters. NO ONE active in the field of behavorial genetics claims to have proved that many individuals today have maxed out their potential for intelligent behavior. There may be (as yet unknown) interventions that could massively change IQ at the individual level.
No one has proved that technology won't one day make everyone grow to 6 feet and live 200 years. In fact that could quite plausibly happen. But you'd still be a fool to count on it.
