The ability of any information processing entity, biological or digital to distinguish, search, find and use the causal paths that this reality uses to build itself then use them to search and design new future paths that lead to an optimal outcome on long term of both the entity itself as well as the entire set of information processing entities as a whole.

That basically means the pursuit of happiness for all.

An intelligent entity can use various tools and models to achieve this task. As part of these tools there is mathematics with statistical tools used to uncover substantive causal paths out of (usually) superficial correlated events that it is exposed to when moving in the space of states of this reality (spacetime and other dimensions and fields).

I do not call intelligent an entity that is not aware if the causal-correlation relationship and confuses one for another.

That being said, I consider all current AIs as non intelligent entities that are capable of mimicking more or less other intelligent entities that for now are only the few of us. Yes, surprise, if you are not aware of this causal-correlation problem then you can’t be labelled intelligent in this definition of intelligence. Also if you follow there is no reference of IQ measures in here. That is irrelevant unless it leads to the required parameters of intelligence.

For our sake and the future of us all I hope that once we get this straight then most of us will become truly intelligent and so being able to build tools to help us in this intelligent endeavour.