Removal of resistance: There are a lot of key questions to ask.
Unification: Whenever I think of trying to explain the basic maths of anything to anyone I have to remember always that most humans for some reason have been very heavily conditioned to believe themselves absolutely stupid and incapable of understanding very basic maths, moreover their minds have often therefore become too lazy to even be capable of doing it, whether or not they are conscious of the fact that they are lying to themselves, or being lied to (and believing it) over the matter of their capacity to do simple 'maths'.
Nonetheless that's just a small issue in the large tapestry of narrative that constitutes 'the dumbing down of society'.
Feynman, when asked about the failure of NASA over the Challenger shuttle launch, insisted that the metaphorical question we have to ask about NASA, rather than pointing fingers of blame, is 'how do you educate the child?'.
For Feynman 'the child' was NASA's management and the educator was science, but not necessarily the scientists involved, whom he paints as brow-beaten by the sales and admin people.
In today's world, as Feynman would no doubt note well, the problem has worsened, not improved, everywhere. Today 'scientists' involved in the commercial part of our society are those who are willing to unscientifically obey the absolute authority of commercial (and thus financial) 'superiors' (or 'lords', 'masters', 'overlords' - whatever word you'd like to use).
Britain's NHS has been a good example of an exception, until recently. Under the Blair government and the tory governments which followed it, doctors have had to give decision-making power and overarching control over to people concerned above all else with profit and personal gain. This may be why Stephen Hawking has such passionate views about the selling off of the NHS.
Returning to the issue of society's dumbing down - decades ago people warned that tv was 'numbing people's minds' - and of course when the internet showed up the last few warnings and cries about this faded out and the horror kicked in.
Hyperconsumerism in many, most or all areas has also been surging in these recent decades, accelerating, and the passive media, ie tv stations, films, perhaps a lot of 'reading' material too, more than you think (George Orwell is right up there with Hello Magazine, some might say, if you're looking for meaningless banter to keep your clockwork mind's hamster spinning in its wheel), all (the films, tv, escapist reading material) along with a lot of the internet ('social' media, much of the online commercial landscape, the vast majority of online 'devices' (ie phones, predominantly, until everyone has silicon chip implants and a part of their brain replaced with state-sanctioned motor control systems!)) is taking people along the road to dumbness at speeds never before seen on this planet, or if ever then so far back in time that our scientists haven't spotted any evidence of it yet.
This is a topic which I think research needs to examine very fully.
In one particularly grim sales job I had to do, some particularly amoral and unwholesome and rich sales company had its pawns teaching other pawns to 'lower the ambition' of their victim, ie the targeted buyer - who had to be someone owning a company with very high equity per head, eg a hugely rich consultancy. The idea was that lowering the ambition of the buyer, with regard to what they might do with 10s of 1000s of pounds to get good contracts, would help you along the road to getting them to pay 10s of 1000s of pounds for your help (their ambition-superior!) in getting contracts worth millions.
So big business, dealing with other big business, seeks to lower each others' ambition and, amongst other things they trained me to do, raise the excitement of the potential buyer, of the decision maker, and then when it is at its peak, put forward the buying dialogue and conclude the deal.
Thus they treat you, reader, unless you are such a rogue as described (how few of those rich enough to be abused by such roguery are not rogues themselves? Very few or a few few? Who knows. We can only guess), even worse (they, the big businesses) than they treat the rogues described. They lower your ambition 100% and make you believe that your life needs to revolve around their products and services.
This is how they have dumbed you down. No one did it on purpose - to them it's just the 'natural' approach to selling goods and being commercially viable and 'cut-throat' enough. People's will to believe that they can be 'above average' or 'not mediocre' is just battered away and eventually removed semi-permanently (for many people permanently, they'll never do the one thing which will restore their self-empowerment, and which they can do at any time of their life, in theory).
The media and commercial-consumer self-feeding frenzy, moreover, is accelerating away, still, like mad, and people are for a lot of their lives in many cases controlled entirely by their belief that being sustained and surviving means having consumer goods of one sort or other.
And it doesn't just lead to the pursuit of wealth - indeed 'the poor' (a term which surely cannot describe the permanent state of any human being in any kind of enlightened society) (see Alex Cockburn's "A Colossal Wreck" for more about that notion) are just as 'guilty' - indeed so many 'working class' persons of various wealth brackets (it's often just a ritual obedience club rather than any scientifically based sense of purpose or identity, in this post-horror world) proudly eat and drink (and smoke) things which modern sane healthy humans know to be lethal, and moreover follow the same patterns in many areas of hygiene and proudly perceive those with actually sound hygiene etc to be weak, biologically 'wrong', indeed their somewhat deranged interpretation of darwinism makes them perceive healthier people and healthier lifestyles as less, not more, survival-friendly.
Consequently the cheap supermarkets and other outlets pouring out so much processed food have a huge consumer base which gladly drives this perverse reality - not just gladly, but often in the manner of crusaders. I have read accounts of healthier-eating persons being mocked by working class peers (and these healthier persons' 'class' designation can be either, it makes no difference to the response being meted out) who consider it unmanly or in some crude way abnormal (hippy, even) to eat and drink in ways which are 'excessively' discerning - a bit like such people and their blind subservience to the belief that democracy is an 'excessive' form of 'people power' and that oligarchy, such as we have it today, married to plutocracy, should govern our world and prevent things like progress or survival from being characteristics of the human race's long term history.
Anyway. More needs to be said, but that's a lot to begin with, really. Click the linked text to go through to various other grid points, often with urls in the references, leading to much more material to read when considering whether or not you're intelligent or whether you are part of that segment of society which is permeated by a latent sense of worthlessness and a need to obey authority to feel assured of a very dubiously interpreted notion of survival.
You may need to read this document more than once to figure out the answer, potentially.