Demagogues, demagogues everywhere.
This is the first of the major changes I can see. As we have millions of voters capable of changing elections, thus laws and governments, then the rise of a younger generation of political leaders is inevitable.
Their entire political agenda is basically youth polities.
The success of such politicians is likely a complicated matter as in this day and age the ability to reach millions of younger, yep young thus more connected, voters insures that the government can start becoming slowly changing.
This process will be different as certain places have different systems and complicated political structure but as long as you have millions of young people who are willing to go elections and the election is free then you will have more of those politicians.
No amount of media watching or reading is going to change the younger generations view. The richest person alive can't influence you to submerge yourself in acid so no matter how large an entity wants person A to be the president the hardwiring will win.
However since you still have older people the global political scene will be more about age politics rather than left or right, or whatever it is before.
This will bring about all sort of large scale changes.
For example a 20 old parliament member is liking going to discuss cutting funds to the seniors programs for obvious reasons.
This won't be lets burn gather them and burn them up but rather more subtle and more devious ways to "handle" older people.
First you go with obvious stuff. No driving past a certain age.
Mandatory sanity checks to determine if they can life on their own.
Less medical coverage.
Even stripping them of their political voting rights based on the idea that the older you are the less you are intelligent so no voting.
This goes into all sorts of things as well.
Jobs, can't keep the same position after a certain number of years.
Maybe even property.
All those are just examples of proposed laws. Some of them are not that radical even. But with more traction and millions of supporters then I leave it to you to implement whatever suits your world.
Interesting point. The more a dictatorship a place is the less likely it would change.
- Messed up relationships and society.
Well. This is just a reasonable thing to assume. You excluded immediate family but strangers are free game. So forget about leaving the seat for an elderly man at public transportation.
But this if far more screwed up. Maybe they dislike classical composers and writers. So bye bye older works.
But even if not the overall society is going to be worse than low level discrimination of any type. Because even if your society was racist only a few badly racist and many people don't care much. But hard coded discrimination against older people is far worse.
It simply insures that 100% of the people are 100% awful all the time.
This gets worse when it is combined with more aggressive people as they won't balk at actual bodily harm.
But also this society won't have a person falling in love with a 10 year difference.
You will must likely not go to piano or metalworking class because the teacher is older.
Heck maybe even films and TV is changed as just seeing an older person makes you dislike them.
So a 35 yo pregnant women is drowning? LMAO.
That parking spot in front of our building belongs to the old man next door? Call the cops.
Even chit chat with random strangers or older people is off the limits.
- Discrimination with the blessing of the whole world.
Ethnic group A might be discriminated against. But as companies found out they make as good workers as the rest of people and in turn they make good buyers.
Discrimination is bad.
Sexual attraction sometimes extends beyond your ethnic group.
Friendships and shared interests.
All those reasons helps to make sure that a reasonable society treats all humans equally. Sooner or later at least. Yes we did have problem but context people.
And we did actually end legal discrimination in most sense. But I don't want this to be about politics. I just want to give an example
I am more likely to be friends with someone from another ethnic group that is nice to me and we do stuff together than a bully of my own ethnicity.
This is why older discrimination is mostly society and bad people and so on.
But the new one?
OH boy. Hardwired into the brain with an uncontrollable reaction to those people.
You don't feel that, unless almost brainwashed, towards other people ever.
But the infected do and that makes sure that the whole worlds changes.
Lets start small.
Mall A has age restrictions. Guess which mall is making more money?
So mall B right across the corner does the same otherwise they start losing money.
Expand all the way to the mega corporations of today. Catering to certain groups and following the directions of the money spenders is economy 101.
Again you can introduce levels of that as you see fit.
Just understand that such a strong prejudice against a large groups will echo in the world of business, ads, job market...etc.
- Experience is going to be a problem.
I think by now you will get me when I say that experience in a certain job mostly comes with time and with time also age.
This is going to be manifested in every field with great levels of difference.
The military is an obvious institute. Can training make people overcome this hatred? You can find an answer.
But for the academic field and most work this is bad.
A 70 professor who might be viewed as a sweet old man and a walking encyclopedia in his field will be view with hatred in your world.
So will we see segregation based on age in the job market?
Perhaps in certain jobs. But as the job becomes complicated then we can see segregation in the work place and usage of non human communication.
Say department B needs department A to do something but they are of different ages, then it is far better to have that request in writing via email or something similar.
Or just in having the work space be completely closed on people as to prevent you from seeing others that will invoke a strong reaction.
I can't imagine what schools will be like. Just a nightmare. I mean school is a Lovecraftian horror filled pit of hell on the best days.
Here not only have you amanged to eliminated the natural human sympathy but you even introduced
hatred in 100% of people. This is not an issue as fear of the law and efficient policing exists so you can expect people to follow the law.
But with such a large group and such strong hatred it only makes sense that the most vocal and violent groups and individuals will be willing to commit crimes of all sorts.
Perhaps just violence or low key stuff. As we all know willingness to kill or really hurt is not easy.
But again with such a large pool you also enlarging the pool of criminals with all sorts of crimes.
So expect even insults and rudeness to be the norm.
- Makeup, prosthetics, and surgery.
I shudder to think of the implication of that idea. In the more extreme cases you will have to wake up a full 2 hours earlier to apply a bunch of stuff, including Hollywood levels stuff, just to get to work in peace and live in peace.
This will also mark an increase in oriental teas and perfumes and all sorts of fake products that will claim to make you 20 years older or younger.
So as usual the actual stuff is going to be a lot more boring and time consuming. Layers of makeup. Fake bit of the face, surgery...etc
Insanely strong perfumes to mask your smell. Even continues injections and homemade de aging or aging machines.
I expect those stuff to be sold by the dozen at every corner
when you see someone you like you get aurosed, see lion get scared,
see tapeworm get disgusted
I could argue that what you describe is easy to overcome for most people.
You can train yourself to face tanks and lions and sharks. You can train yourself to eat anything. Arousal is a tougher thing but you can control. Not to mention that sometimes we see someone we dislike so much that we want to engage is sexual activities with in a certain manner.
However that seems to be counter intuitive so I will simply say that there will always be few that will learn to look beyond that and they will be the better for it.
A company that can recruit people with such huge gaps in age can do better. Personally if you are willing to listen and deal with people based on pragmatic terms in is better...etc.
Wealth complicates thing because if I have to clean the pool of the 50 year old couple to get some money then it might only add to the hatred.
But even the larger context is present in the job market or life.
In fact the older most people get the more wealth and influence, on whatever level that is, they gather and so that might add to hatred.
And the ghettos part is self explanatory. If you are not wealthy have guards and dogs and cameras then a little suburbs where only the elderly live makes more sense.
- The Matthew effect exists.
Whenever I read a question with a thing I always consider the Matthew effect on the matter.
Here is an example
A is a handsome genius born to billionaire caring and good parents then inherited their wealth, but also he is industrious and diligent and ambitious.
That man should have the world and continue to grow in wealth. Actual billionaires as an example.
But B is born a sickly average child to power middle class parents.
Yeah. Not looking good for him.
So things usually go further than the original premise. So that is why I tried to push certain ideas to the max.
I hope it helps. I get that this is a big question actually so guess you can ask in a certain context if you more more specific answers