ignore vs look down on

[keannu]

I learned from a native speaker that "ignore" just means "don't pay attention to sb/sth", while "look down on" or "despise" means "to disregard to disrespect" someone. But the following examples seem to have the nuance of "despise", so please tell me the difference between "ignore" and "look down on".

ex1)They ignore their siblings or the rest of the family
ex2)Don't even ignore hewers of wood

[keannu]

To ignore is to not pay attention. I can ignore you and I can ignore the clicking sound in the engine of my automobile.

To look down on is to assume that you are somehow superior to someone else and, thus, perceive that they are inferior to you. It is like you are standing up and looking down on something on the ground though this phrase has more to do with a psychological feeling.

Okay, perfect!!!, but what are these? These are not related to despising, just meaning "not paying attention" to the objects?
ex1)They ignore their siblings or and the rest of the family
ex2)Don't even ignore hewers of wood

[keannu]

I can ignore a loud radio without despising the radio, the music, or the other sounds that the radio makes. I could ignore you because I despise you but I could also ignore you because I am busy doing something else. Whoever told you that the term is only related to something despised had a limited understanding of the term.

I think you mean "igonore" ultimately means "not paying attention to" but the reason can be various such as "being busy", "despising the other party", "don't want to be related to that person", etc. So I can just interpret the meaning as "not paying attention" as the final result, Right?