So, do we know what decides if a person develops to become more greedy, agressive and selfish while another becomes altruistic and doesn't care much about wealth and power?

Lead exposure in childhood is one thing we know leads to poorer impulse control; that is to say, being short-sighted and selfish.

This is basically the old nature vs. nurture debate.

We all know of course the environment in which you grow up seriously influences your personality, however a surprising amount of human personality is attributed to genetics. There are case studies of twins separated at birth that will give you chills, as well as adoption studies where personalities of adopted children are more in alignment with their bio parents than the parents who raised them.

There are two personality "disorders" described in psychology that are commonly associated with the behaviors you're describing. Antisocial personality disorder is characterized by a lack of empathy, disregard for cultural norms or rules, and engaging in behavior that harms others. Narcissistic personality disorder is characterized by a lack of empathy, a relentless focus on self-promotion and self-preservation without regard for how one's actions affect others, and a drive to project power or status, no matter how real or imagined that power may be. Both of these disorders seem to have some degree of heritability associated with them, but it's not super clear cut, and it's likely that even with a genetic predisposition someone has to be brought up in a certain environment for the disorder to develop.

All this said, even more of human behavior is culturally and socially bound. Go back in time 1500 years, for example, and war, torture, execution, rape, and more were much more prevalent and socially acceptable than they are today. Even today there are cultures that tolerate more or less of each of these things.

This is my completely unsourced two cents

I think it's most to do with exactly how much wealth a person was born into.

Someone who is constantly on the verge of being homeless, possibly even starving, will very soon get desperate enough to do things they aren't proud of to survive.

On the other hand, someone born into immense wealth will have very little understanding of people who are struggling. That'll make it very hard for them to empathize. And with all that power, their sheer indifference will have them crushing the poor under their boots like ants. This is highly exacerbated by the fact that it is in their best interest to support policy that transfers wealth upwards.

The anthropologist Sarah Blaffer Hrdy has theorized that empathy and altruism are acquired in early childhood by observing when one’s caretakers show empathy towards oneself, which both gives infants a sense of security in interacting with other people and which, because babies learn through observation and pattern recognition, establishes a standard in their minds that tells them humans are supposed to be selfless and kind to one another. This theory is relevant to us because, since most of us live in decaying neoliberal hellholes, many people’s parents are too busy working to give them appropriate care during their formative years and are not rich enough to pay for people who are qualified to do so in their stead. When it comes to people whose parents are rich, the selfishness that lead to them accumulating wealth could get passed on to their children by the same method. In other words, the conditions created by capitalism could be fucking with the ability of infants to become good people later in life

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I don't have an answer to you but if you like this sort of discussions/topics, I highly recommend the book Behave by Sapolsky.

Yup. Nature aaaand nurture. There are countless studies and conversations and theories about this, but given the sheer number of variables and the very difficult question of "is anything you experience experienced the same way by others?", there aren't many definitive answers and no universal answers.

If you had the ability to push a button and divert $0.01 from a random million US bank accounts in a way that would leave no trace, would you press the button?

Power corrupts. Most people are not strong enough to resist the abuse of power. It starts very small - such a minor, harmless thing, but then you abuse power more and more to cover your tracks or to benefit yourself more.

I would guess a person's life circumstances. Humans tend to reflect pain they're experiencing onto others. If you're hungry, that's a form of pain. If you're neglected, that's a form of pain. Even the sons of billionaires experience pain, probably in a way that's hard for reg folks to grasp.

Also, I think your dopamine regulation being all messed up might also contribute. Those people who seem to flail and rage because nothing can seem to satisfy them.

Also, everyone does terrible things and hurts others. You can be charitable and kind from one perspective and an oppressor in ways you won't allow yourself to see. We all do it.

We know that people who have less tend to be more generous than people who have more.

A lot of those shitty things aren't normal in humans, but become much more common if you force them into violent, existential conflicts.

And insatiable greed is promoted as good at almost every level of neoliberal society, so that one should be self-explanatory.

People just say "human nature" as an excuse for their own conservatism

I really like this question and it is one I think about a lot when daydreaming since having kids. When would I know if they've gone bad? If they do end up antisocial or narcissistic will I be able to point to a situation or chain of events that caused it? Will I even know?

Empathy is probably your best bet as far as a single variable goes. But otherwise we're talking about something that's incredibly complex on multiple levels, making it near impossible to address as a whole.

I like to envision human behavior and consciousness as a network of tensions and influences. (Perceived) material interests are one such tension, a particularly strong one. Strong enough that I feel confident saying that in general, people will tend to drift towards approximating an ethic that aligns with their material conditions.

The archetypes and behaviors modeled for us in our childhood and throughout our lives are a sort of structure that these forces interact with. We may have empathetic or selfish responses modeled for us by our parents, so those are the responses that spring to our minds when decisions arise. Good behavior modeling could mean the inherent tension towards self interest may be mediated or tempered by the limits of behavior we think to enact. Parents have a big impact on this early on, but so do later role models as well as media portrayals of people.

Social cohesion can be a big tension on people, incentivizing them to not act outside of group norms out of fear of being ostracized. Or on a more subconscious level, perhaps acting out of a "self" interest that benefits the social group, because the lines between Self and Other become blurred. Extending beyond the small self to consider the well-being of the large "Self", sometimes even at the expense of the small self.

Critical theory may be of interest to you.

This guy wrote a book a long time ago which goes into this. Something about 'material conditions'?

While I'd say altruism is not a virtue the way it is defined in our culture, I will say that who we are is about 50% nature and 50% nurture, and inside we are very different beings for one reason or other. A born sociopath is only human the same as you in visible form, the being is nothing like you. A person who was badly abused and tattoos his face and perpetuates abuse on those around him is completely different from you both. A monk in a monestsry and an Instagram influencer are completely different beings inside, besides some basic neurology that makes them both human. If you could see the being inside every human they'd look as different as Pokémon. That's my philosophical insight.

Great question. No.

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Skyward fan?

No. Though everyone has ideas about it.

There is no one factor that dictates whether someone becomes good or evil. What matters is getting rid of people who are evil for our own benefit, liberty and happiness. To dispute that is to imply people should suffer evil against their best interests, an inherently evil position, so it can be dismissed off-hand.

The long branch is the long arm of altruism, the short branch is the short arm of altruism.

Back in the days only people with a strong will to survive did, infact, survive and the genes from those people are in all of us. Many like to pretend they don't posses these features but that's only because you're living a modern comfortable life, so you never need to rely on it. Especially compared to what it would've been 10k years ago.

You can take any modern man, and put him along with his family in a house and place an angry stranger pounding at the door shouting threats at his wife and kids and you'll soon discover the violence you just thought wasn't there.

Power corrupts. I’d say probably 95% of people who consider themselves altruistic, if you gave them significant power, would end up abusing it before too long.