So many people that take psychology courses end up working in the advertisement industry because that's where the jobs are if you have a psychology degree. Very few people sit back and think about the implications of the scientific study of the mind being used by companies to distort peoples perceptions and make them buy things.
They are literally trying to control our minds. It's not a conspiracy theory this is out in the open public information. If some companies decided to they can make you depressed to sell more things to you and you wouldn't even know it.
Imagine the pick a teenage boy. This boy is a bit shy and insecure. Now, psychology was originally intended to help people. Under the capitalist model it doesn't. Now this teenage boy instead of being recommended stuff to help them will instead be recommended the likes of Andrew Tate and so on. This person won't even know what hit them and won't even understand the turn of events that will lead to those videos being recommended. But they are recommended to him. Suddenly his change in behaviour pushes people away and he falls deeper and deeper into a rabbit hole.
They get more depressed. More lonely so they start buying shit like AI girlfriends but they aren't real. They get recommended more hateful content as well. They will sprial deeper into depression. This person will likely seek help at this point. Perhaps they'll recommend putting effort into real world connections so they download something like tinder. But all these apps are designed to make you pay in order to succeed so he pays to get special access. Now the ad companies know they'll loose money if this now grown man becomes confident so they start recommending content that'll make them more anxious and depressed about the experience. They give up and retreat further into depression. The whole time the person who is being targeted, their family, their therapist and their loved ones will never be able to put the dots together. They'll wonder what went wrong not knowing that their personality was already decided for them by ad companies years ago.
So like that they add companies weaponising human psychology can target a teenage boy and basically plan out the next ten years of their life. Think about how dystopian the weaponisation of psychology is when a family member of yours goes down the alt right pipeline after "suddenly" being recommended such videos.
Building on this, I also want to warn against the attitude that 'ads don't work on me'. A lot of people seem to think that they have some kind of mental filtering system such that they are immune to manipulation. They sometimes talk about how they deliberately make a point of not buying from some company who advertised in a way they didn't like, or whatever.
I'll just say this: you don't have a special power. The ads do work. Maybe not every ad has the effect that you think they are aiming for, and not ever ad is targeting you. But if you are exposed to advertising, then it will affect how you think - and some of the people making these ads are serious experts with lot of research to help them manipulate your habits and behaviour. It's a type of social technology that has advanced over time. It's better to avoid it rather than assume you are immune.
I.e. you are not immune to propaganda
I am digging up this old thread to add that the social media scrolling epidemic probably employs a behavior modification technique named 'partial reinforcement' when the desired behavior is not always rewarded but occasionally https://www.simplypsychology.org/schedules-of-reinforcement.html#Partial-Intermittent-Reinforcement-Schedules The learned behavior is stronger. You see people scrolling endlessly even in platforms there is no advertising. Or you see people, even the Internet is out, they will still kill some time on the computer or phone playing games they would never open otherwise. They have been conditioned to be in position to consume "content". This persistence of learned behavior is typical of the partial reinforcement schedule. Now what is the reward? Perhaps rage, arousal, or other stimulation. You scroll and scroll anyhow, till something dopamine-inducing comes up. The behavior persists even in other platforms. If you are interested I have started a thread about an attrition approach to major platforms (https://lemmy.ml/post/17679530/12103132), and what OP calls the weaponization of psychology by advertising platforms is something that doesn't sit well with me, from a humanitarian and anarchist perspective.