I have always tried to be respectful, since being a kid, to everyone that I have met. The only people I have disrespected are the people who have gravely wounded & disrespected me. It was never anything personal; simply a matter of integrity.
https://www.acas.org.uk/discrimination-and-the-law/direct-and-indirect-discrimination
https://www.acas.org.uk/if-youre-treated-unfairly-at-work/being-victimised