Just to extend a bit further, I think it is actually more immoral behavior that societies ingrain into people. I think immoral behaviour is more learned behaviour and loss of self. As examples I will point to hatred racisim war selfishness. These things when created propogate themselves. I dont think any baby is born racist or wanting to invade another country.

I will put fourth the idea that there is some form of innate morality. Best described by the golden and silver rules. I put this forward based only on my on personal experiences in life. Though being good vs feeling guilt and shame; seem obvious. I know you could argue that those are societally ingrained into me and I would say yes that is part of it. Though I would in turn point out that if there was not also a physical aspect that caused a natural sense of morality societies would have been very difficult to form. The understanding of mutual benefit comes from a sense of morality I think.

I gave examples of both as well as the only disturbing logical argument I could think of for not pulling the lever.

Morality is difficulty especially in a case like this as you decide life and death. I think there could be arguments for both. By acting you kill someone and kind of save 5. Through inaction you hold some responsibility for the death of 5. I think what would be most relevant in the decision making process is what if any knowledge of the 6 people you have.

Do you know any of them? Do any of them have a visual appearance that you can relate to from your own life experiences. Theses could impact the decision making process. Excluding knowing the 1 man I think you probably just switch the the tracks. My reasoning for thinking this is simple greater good.

If 1 man dies one family and one set of relationships suffer. Where as if 5 die 5 families and relationships are hurt. I do not say this is the morally correct decision and would have to accept that I had killed a person by my actions. If I had to make a choice between letting 5 die or killing a different one by pushing a button. I would push the button. Though again this excludes all other possible relevant factors. (Though if someone did not make a choice but froze in indecision I would not call that immoral.)

The only arguments I could see for not pushing the button would require more information than provided. Excluding if you believe population reduction is actually in the greater good. Which one could make for an argument for that though its kind of a dark one.