You are making a few mistakes: * technology accretes even if the quality of the average worker is declining across time. Thus tomorrow will still be better tha

You are making a few mistakes: * technology accretes even if the quality of the average worker is declining across time. Thus tomorrow will still be better than today, at least from the point of view of things like technical advancement, regardless of what is happening within each person. * population increases, so the smartest can still be smarter even if the average is declining * Even if population is not increasing, improvements in communication and replication technology can mean that an increasingly smaller share of the brightest people anywhere in the world can design products that are replicated or simply assembled by masses of others, whereas in the past this required local designers. Think of how many people are truly needed to keep advances in jet engines happening. You have basically three companies that supply all the engines to the entire world. * And one can even make up for the other -- e.g. in previous times all shoes were handcrafted, now they are mass produced. Thus a lower skilled person in a later period can still outproduce a higher skilled person in a previous period. Now I'm not saying I necessarily buy the decline thesis. It's an intriguing thesis, basically that you can be pretty dumb and still thrive well enough to keep reproducing whereas in hunter gatherer societies you would have starved to death and so the population would on average be smarter due to the challenges they had to overcome. Maybe this is true, maybe it's not, but the objection that knowledge accretes does nothing to prove or disprove this hypothesis.