If those don't scare you, then I don't mind confessing they scare me. And to forestall the "
I refuse to take anything at face value crowd unless proved to an impossible degree" crowd, I've actually spoken to the student who took the first one. To the best of my knowledge, those lecturers are teaching what the slides suggest they are. That everything is a social construct. That idea was profound to me when I was seventeen. I have since realised that fire still burns you and your brain knows it is painful no matter how many people consciously try to define it otherwise. Reality is that which is independent of our beliefs.
There are many reasons why perception does not match reality. Sometimes it is simply a case of reality being larger than perception and different people seeing (through choice or information availability) different facets of the same thing.
On other occasions it is a difference in informal (i.e. not scientifically quantified) definitions or value.
And sometimes people just bring their own ideas and don't look past them.
But by FAR the largest cause of perception being at odds with reality, is people seeing what they really want to see:
Which is why Trump was probably a good example for the OP to pick because entrenched views are so often demonstrably in contradiction to fact. This article on Trump is hugely useful to read, though it will take people 5 - 10 minutes to read so probably take-up will be low. Everybody's got time to insult people online but nobody's got time to quietly read something. However, it gives many examples of public perception being wrong on Trump and is a very good read.
http://slatestarcodex.com/2016/11/16/you-are-still-crying-wolf
[*]Public perceptions amongst some are that Trump is a White Supremacist and KKK lover. The Clintons provably have had close ties to the KKK. Trump has none.
[*]Many media outlets and online commentators repeatedly accused Trump of not denouncing the KKK. He has done so on numerous occasions going back decades.
[*]Trump is portrayed as an enemy of minorities. He increased support with every main ethnic group in the USA
except White people.
[*]Hillary Clinton secretly accepted large donations to her Foundation by Russian nuclear interests before heading meetings on the sale of Uranium to Russia nuclear industry and the DNC paid a large amount of money to a company for information on her political opponent from Russian sources. Trump has nothing comparable in regards to Russia.
None of the above is incorrect. Each of the items is something that large blocks of people believe without question even though it is wrong, however. I expect attacks on the above from people in this thread, for example. People react badly to information that contradicts their worldview. This is established psychological behaviour common to any human. Challenges to one's beliefs are held as threats. Because they are held as threats, people respond to conflicting information with aggression. Because they are held as threats, Left-wing academics and Social Justice Warriors regard them as aggressive behaviour. I have, quite literally, been told that it doesn't matter if what I said was true or not, it's wrong to say it. Because to some people if reality is less favourable than perception, insisting on reality is an imposition of power over others. Hence lecturers like those at the start of my post who want everything to be a social construct. If science and facts are a social construct, then that is to say science and facts are subordinate to social judgement. Which is an attack on anyone who pushes truth over belief.