Leave mental disability out of it, because it's not relevant to the discussion.
What's clear to me is that people have different learning rates and different need for personalized attention. I also would never argue with the assertion that some people have greater natural aptitude for specific things, meaning their ability to pick up the material at a standard pace without a lot of extra personalized help.
There's plenty of research showing that IQ exists and can be consistently measured, but I would hesitate to ascribe the learning outcomes in a higher-level math class directly to IQ. If assessing general intelligence were easy, we wouldn't need decades of psychology research on the topic. So I personally don't think we should be in the business of trying to assess how smart people are in general. Assessing attitude at specific tasks can of course be practical and useful.
That said, have you asked your colleagues for clarification on what they mean by "everyone can learn"? Are they talking about learning it on a hand-wavy pop science level (eg Numberphile), or learning it well enough to derive results and apply it in new problems? Do they have a timeline in mind for learning, or a specific context? Are you sure your colleagues are being dogmatic for fear of confronting uncomfortable truths, or are they just optimistic? Or have they forgotten that algebra is pretty esoteric and far away from what people normally deal with in their day-to-day lives, and might actually be a specialized topic that does require a bit of specialized natural aptitude?
What's clear to me is that people have different learning rates and different need for personalized attention. I also would never argue with the assertion that some people have greater natural aptitude for specific things, meaning their ability to pick up the material at a standard pace without a lot of extra personalized help.
There's plenty of research showing that IQ exists and can be consistently measured, but I would hesitate to ascribe the learning outcomes in a higher-level math class directly to IQ. If assessing general intelligence were easy, we wouldn't need decades of psychology research on the topic. So I personally don't think we should be in the business of trying to assess how smart people are in general. Assessing attitude at specific tasks can of course be practical and useful.
That said, have you asked your colleagues for clarification on what they mean by "everyone can learn"? Are they talking about learning it on a hand-wavy pop science level (eg Numberphile), or learning it well enough to derive results and apply it in new problems? Do they have a timeline in mind for learning, or a specific context? Are you sure your colleagues are being dogmatic for fear of confronting uncomfortable truths, or are they just optimistic? Or have they forgotten that algebra is pretty esoteric and far away from what people normally deal with in their day-to-day lives, and might actually be a specialized topic that does require a bit of specialized natural aptitude?