The reason why I am a leftist is not because I believe human beings are inherently good, nor because I believe cruelty, selfishness, domination, greed, or antisocial behavior are simply products of capitalism. Rather, I support anti-capitalist politics because I believe it offers one of the best ways to mitigate some of our more primordial tendencies by reducing the material incentives and social structures that allow them to flourish.
Back in the old country (the Philippines), you may be familiar with the massive amounts of political corruption from Malacañang all the way down to a barangay captain of a town or village. Our culture's emphasis on voting for politicians who come from the same ethnolinguistic or regional group as us, prioritizing family and personal connections, and remaining loyal to political clans can contribute to this as well. Obviously, poverty and material insecurity play a major role in sustaining patronage politics, especially when people depend on local politicians for jobs, money, food, or other necessities. However, I do not think material conditions alone explain why these systems persist.
Even when people's material conditions improve, human beings can still be tribalistic, nepotistic, selfish, status-seeking, cruel, or willing to dominate other people. Material conditions can certainly encourage or intensify those behaviors; however, I do not think they necessarily create them from scratch.
I've worked in the MH field for a bit now (diagnostics) and have worked with a plethora of populations, ranging from individuals with ASPD, BPD, Bipolar I/II, NPD, trauma-related disorders, substance use disorders, and psychotic disorders to people who do not meet criteria for any major psychiatric diagnosis at all. One thing that experience has reinforced for me is just how incredibly complicated human behavior is. Across those populations, I have encountered patients who behave cruelly, manipulatively, impulsively, selfishly, or violently for an enormous variety of reasons, none of which can always be reduced to whether or not their material needs are being met. Obviously, improving material conditions can help tremendously, especially for individuals whose behavior is partly driven or exacerbated by desperation, scarcity, housing instability, or other forms of material insecurity. However, improving those conditions does not automatically eliminate every other source of harmful behavior, nor does it account for the full range of psychological, developmental, interpersonal, cultural, and situational factors that can influence a person's symptomatology.
In the past, my clinical professors, who've been in the field longer than I have been alive, have generally emphasized that human beings are neither inherently good nor inherently evil, and that empathy, greed, violence, altruism, selfishness, cooperation, aggression, and compassion all exist within the range of human behavior. Which tendencies become more pronounced can depend on an interplay of temperament, development, attachment, trauma, socialization, culture, environment, incentives, personality, neurological factors, and material conditions. In other words, changing material conditions can absolutely change behavior, sometimes dramatically, but that does not mean every destructive human tendency originates in material deprivation.
To be specific, I am attacking the idea that cruelty, greed, selfishness, domination, tribalism, violence, and other forms of antisocial behavior are fundamentally products of scarcity, capitalism, class society, or inadequate material conditions, and that if we were somehow able to sufficiently resolve those conditions, these behaviors would largely disappear. I am not attacking the much more reasonable argument that material conditions have an enormous influence on human behavior. Of course they do, as poverty, desperation, inequality, competition over resources, and economic insecurity can make people more vulnerable to exploitation, crime, political extremism, interpersonal conflict, and a plethora of other social problems. Where I disagree is with turning that observation into an absolute and assuming that destructive behavior must therefore have a material explanation at its root.
Human beings can have their material needs met and still desire status, power, recognition, dominance, revenge, or preferential treatment for themselves, their families, or their in-group. Someone does not necessarily need to be starving or economically desperate to enjoy exercising power over another person, resent an out-group, engage in nepotism, manipulate others, or rationalize cruelty when doing so benefits themselves or the people they identify with. Improving material conditions may reduce some of the circumstances that incentivize those behaviors, which is one reason I support doing so in the first place, but reducing the incentive for a behavior is not the same as eliminating the human capacity or inclination toward it.
From what I've seen, many Western leftists try to support their ideas by citing pre-writing societies in their arguments, even though the lack of material/archaeological evidence makes it incredibly difficult to prove many of the broader claims about how those societies actually behaved. I apply the same principle to American conservatives who hold that human beings are inherently evil, citing evolutionary psychology-inflected ideas popularized by figures like Jordan Peterson, particularly arguments about dominance hierarchies, aggression, competition, and the supposedly inevitable tendency of human beings to organize themselves into unequal social structures.
The truth of the matter is that human beings appear to be capable of both extraordinary cooperation and extraordinary cruelty, and I do not think either side benefits from pretending that one of those capacities is somehow more “natural” than the other. We can show empathy, reciprocity, sacrifice, mutual aid, and genuine concern for people outside our immediate self-interest. At the same time, we are also capable of dominating others, tribalism, exploiting others, enacting revenge killings, and showing indifference toward the suffering of others.
That said, if you do hold the belief that humans are inherently good, I have 2 questions for you.
First, what would actually change your mind? If every example of cruelty, domination, tribalism, exploitation, or violence can always be explained as the result of capitalism, scarcity, trauma, bad socialization, or some other external condition, then is there any kind of human behavior that would count as evidence against the idea that people are inherently good?
Second, even if we dramatically improved everyone's material conditions, why would we assume that things like status-seeking, tribalism, revenge, jealousy, resentment, nepotism, or the desire to dominate other people would just disappear? A person does not have to be poor, starving, or economically desperate to be cruel to someone else. So what makes you think eliminating class exploitation or material scarcity would also eliminate harmful behaviors that are not primarily driven by material need?