Good question. I think the main difference lies in the experience level of the practitioners and stakeholders using the two, Cooper personas or Indi Young “thinking style personas.” Because either approach is fine to use if they are created from primary research qualitative data, have clear behavioral distinction, and keep to the focus and context of the experience being created. Both persona methods/approaches result in this if the method is done correctly.
When created by a less-experienced team, or when used by less-experienced stakeholders, this is when assumptions come in. Even if the personas are created by a mature team, a less experienced stakeholder can go haring off making up scenarios based on assumptions that they use the persona as a starting point for. The product experience will suffer. This is when my style of personas come in handy.
The primary thing Alan (and Kim) and I are after is allowing teams to use cognitive empathy to walk in others’ shoes. But, cognitive empathy cannot form based on a persona consisting of preferences, opinions, statements of fact, and demographics. You can only form assumptions from these. Cognitive empathy requires inner reasoning, emotional reactions, and guiding principles.
I have seen Cooper personas written at this valuable depth. They exist.
It’s harder to get to the depth required for cognitive empathy. It’s harder to collect inner reasoning, emotional reactions, and guiding principles, which is why we see practitioners making up the details of their personas and having fun getting creative about beyond the context of the product. (Again, experienced practitioners do not do this. But we have a LOT of new practitioners gearing up, and it’s vital that we give them a good understanding of why this is important.)
With my “thinking style” behavioral audience segment version of personas, I try to keep practitioners and stakeholders on the straight-and-narrow. No free-form invention (which isn’t part of Cooper’s approach, either). No demographic details that seem to pin a group down to one type, and might cause practitioners to make another version of the same persona just with a different demographic. Just the depiction of a groups “thinking style” philosophical approach, paired with the focus of the Agile sprint in terms of the tower(s) of the mental model diagram, which you can then use to write the scenarios and then go into creative concepting. You can derive different IA or inventories for copy writing. You can see links between functionality, data models, etc. It’s all laid out and cross-referenced, making things a bit easier to check off on the journey toward a good product the supports different kinds of people.
My favorite part is talking to stakeholders about one persona/segment and bending their mind by offering several opposing demographic examples of this same persona/segment. It really opens peoples’ minds.