I believe the author is correct that statistically, most intelligent alien species are likely to be less populous, and more physically massive than, human being

I believe the author is correct that statistically, most intelligent alien species are likely to be less populous, and more physically massive than, human beings. That being said, at least in the blog post — I haven't read the paper the author also wrote on the subject — there's one critical error, where the author assumes that because most alien species are less populous and more massive, if we ever successfully contact one, we should expect our own species to be more numerous and physically smaller than the contacted alien species. But that assumes contact is based on a random distribution of species! It seems much likelier that contact would be biased just as population size is: that is, we are more likely to contact aliens from a more numerous species than a less numerous one, because they have more spaceships and satellites and listening devices, etc. Using that framework, the contact case actually inverts: the most likely species to contact is the most numerous one, and while it is likely that we are among the most numerous intelligent species, it's not likely that we are the most numerous — at least, not using the country-based datasets. Therefore, it's likely that even though the author is correct that we are more numerous than most, in general alien contact will seem to contradict this, because we will likely be contacting the (relatively few) species that are more numerous than us. We are most likely the Pakistan of the galaxy, but we are also most likely to contact galactic China — not galactic Iceland. The contacted species will also likely be physically smaller than us, for the same reason: contact is biased towards the largest populations, and species with large populations are biased towards physical smallness for thermodynamic reasons. Edit: I read the author's paper, and indeed, the error is not present in the paper (which presumably received more scrutiny) — it's only present in the blog post. The paper instead claims that our nearest intelligent neighbors are likely to be less numerous, physically larger, and from smaller planets — which seems correct. The conclusion of the paper speculates that it may be more useful to search for nearby neighbors than more-numerous far away neighbors, and thus we should prioritize searching nearby systems that have smaller planets (since that's where the neighbors likely are). I'm not necessarily sure that's true — it really depends on whether physics allows reliable semi-FTL travel such as stable wormholes — but it's an interesting take and not immediately controvertible.