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.
Losing a tire in my car won't make me lose any horsepower, but it's not going to be the same ride.