Humans are the only known organism to do System 2 (which doesn't mean we're the only ones that do it, just that we don't know if whales do it), but System 2 is what the author is talking about when they refer to Chains of Thought.
System 1 is what they're referring to when they talk about Messi reacting to an unusual situation on the field.
Related anecdote: I tested myself for ADHD by taking amphetamines. I normally think by intuitive leaps from point to point, without doing the intermediate steps consciously. I found that during this experience my System 2 thinking was fast enough to follow and I actually experienced proper chains of thought. Or I was whizzing my tits off and hallucinated the whole thing. Not sure yet. I should repeat the experiment.