> "You seem to be confused about what a measurement is. It is defined as mapping numbers on empirical phenomena. This is not a matter of Psychology, this is the definition everyone uses."

I have no problem with that. My problem is with how that measurement is used in wider society. I'll explain further later in this comment.

> "So, yes, "memory span" is a measurement of mental capacity: Following a clear procedure, it assigns numbers to a construct we call "short term memory capacity"."

Perhaps you're misunderstanding why I'm hammering on the 'capacity' angle. When someone is tested as having an IQ of 200, the collective understanding of that number is that it's a number that's more or less fixed (outside of illness or old age). If someone gets an IQ test score of 200 one day they're not expected to get a score of 150 another day. Whether that's accurate from a scientific point of view or not, that's how it's seen within society at large.

So, from that more general perspective, capacity is seen as total capacity. It's this I have an issue with, not how it's used within academic journals. I've never taken a formal IQ test, so this isn't a personal issue for me, I only object on the point that a model with a single metric can describe total mental capacity.

> "A measurement is essentially a model of something, so by definition it reduces something complex to something more simple so that we can study it."

Fine, but are we measuring the human or the model? Let's say I design a competing model of human intelligence that only loosely overlaps with IQ but still has the potential to predict future success. At this point, do we need a new model that can encompass both? Does the existence of this competing model make it clearer that each approach has limitations? If you don't want to get into discussions about the above, why do we measure intelligence in a fixed way but not other human traits? Why isn't there a formal model describing capacity for love? What gives us the confidence to simplify one trait to a model but not others? Is it because we have faith in the testability of those models? Isn't then the foundation of the model a style of questioning that promotes reproducible results? How do we choose the subset of potential questions that best capture the full range of intelligence?

> "EQ was the work of a journalist who did not have the background in Psychology to understand that there never was a shortfall to begin with. Differential and personality psychology has been working for decades on these topics. EQ has added no insights."

Perhaps there wasn't a shortfall in the world of psychology, but there was a perceived shortfall in public discourse. I think this is the crux of our disagreement, you're approaching IQ from the scientific angle, I'm approaching IQ in terms of how its used outside of science. Scientists should be the authority in how the model is measured, but that model doesn't solely have an impact in the scientific community, it has also become a cultural touch point representing intelligence. Whether that is an appropriate use of IQ or not is up for debate, and for all its flaws I see EQ as a way of furthering that debate.