Earlier quoted context omitted.
I've heard the best predictor of performance on IQ tests is number of books read. In my experience, reading a book forces me to conceptualize the content in a way watching TV and listening to audio does not. It is also faster than watching and listening. I think this has improved my conceptual thinking ability, as well as being able to articulate my thoughts, and expanded the number of concepts I can use in my thinki…
I think reading books correlates with IQ, but it does not increase it; it provides information and stimulate imagination and analytical thinking, but there is no known method to increase IQ.
On the other hand, the less sleep I get, if I am out of shape, feeling depressed, etc. all have a negative impact on my cognitive performance.
So, while there may be individualized hard limits on cognitive performance, it also seems clearly the case that an individual's cognitive performance can be greatly improved through various habits. Think of it akin to athletic training. Some people are born with an athletic predisposition, but everyone still benefits from working out, training and diet. Hard to see why the same cannot be true for cognitive performance.
Now, taking the topic of reading vs more sensory media such as TV, the former require more internal cognitive processing to understand, whereas the latter minimize the amount of focus needed to consume the media. Based on my previous analysis, it would make sense that a reading habit would produce a higher cognitive performing individual than just consuming sensory media.