Certain types of medications can potentially make people more intellectually active.
There is a concept in neuroscience called neuroplasticity. One important fact about neuroplasticity is that it declines with age, particularly it undergoes a sharp decline around or after puberty. This decline is a major reason why people have trouble learning foreign languages after this age. People who learn the language after the neuroplasticity decline are much more likely to speak with an accent, no matter how much effort they put into it. In the last decade there were some major discoveries made in this field. Particularly, the protein that naturally inhibits neuroplasticity in humans with age has been identified. It is called PirB. Its inhibitor is also identified by the same group that published this article. Potentially, a PirB inhibitor would re-enable neuroplasticity and allow people to learn things easily, to form new neuronal connections like they did while they where children. It can bring back a lot of mental freshness and learning abilities that people normally lose with age. This likely can significantly boost person's mental abilities, and make people more intellectually active. I think they are trying to get the FDA approval for the PirB inhibitor to be used as a treatment for amblyopia and Alzheimers. But the plasticity decline itself isn't a disease, so it's unlikely that it will become an officially approved drug for this purpose.
It is interesting that in the book that you mentioned and in your writing there is an underlying assumption that life originated on Earth from scratch. There are scientists that believe that life could have been introduced by outsiders, see for example this article by Rhawn Joseph. There is also the Drake equation used to estimate the number of extraterrestrial civilizations. There are NASA missions, like TESS, discovering more and more planets with Earth-like conditions.
Life on Earth could be an experiment set up by some advanced civilization biological origins of which might be entirely different from ours.