Why having kids is evil; an evolutionary thesis of evil
Neuropsychologists and ethologists have widely distinguished between two primary forms of aggression: Predatory aggression and reactive aggression.
Reactive aggression is characterized by hyper-limbic activation (activation of the emotional parts of the brain). Species that have been prey animals and animals which compete within a social hierarchy (which includes us) have evolved reactive aggression as a mechanism to either defend against predatory assault or defend status. A good example of reactive aggression in human beings is a man hitting his spouse after a particularly nasty comment. It's emotional, raw, and done in anger. There are many species that have evolved highly limited degrees of reactive aggression. Examples include Manatees and Bonobos. They're very hard to piss off and quite friendly. Manatees for example have no natural weapons. They have no sharp teeth, blunt objects, etc on their body. They're very chill.
Predatory aggression is characterized by hypo-limbic activation (quieting of the emotional parts of the brain). Species that have had the problem of having to hunt (which includes us) have evolved predatory aggression as a mechanism to reflexively kill and chase prey animals. An example of predatory aggression in human beings would be threatening to shoot someone while robbing a bank if they do not comply. It's cold, calculated, pre-meditated, reflexive, and goal-oriented. A zeroing in on a prey. There are many species without any predatory aggression at all. Rabbits for example. They aren't even tempted to swat a fly.
The reason why us being mammals is interesting is because as mammals we are also evolved to display what is known as maternal solicitude which is the deep concern and compassion a mother has for an infant. There are species with virtually no maternal solicitude like for example crabs. They even eat their infants. It makes sense that predatory aggression and maternal solicitude (as neurological functions) would inhibit (stop) one another as a neurological function. A species that could spontaneously go from grooming their cooing infant to punching it in the face repeatedly wouldn't survive very long,
It also makes sense that different organisms vary at an individual basis in their expression of maternal solicitude and predatory aggression. Male grizzly bears are so predatory that they have no problem straight up killing cubs in order to copulate with the women and then they completely avoid the cubs. Dimorphism is the most common expression (difference between sexes) of variation in predatory aggression. Although human males are considerably more maternal than grizzly bears, they are nonetheless more predator-like than human females. That might explain why the vast majority of instances of animal abuse for entertainment is committed by men.
It makes sense that individual variation exists even within the male sex. Some guys are chill and nice. They're not very predatory or reactive. Other guys are very hostile. They're just fuming with anger and chronically burdened by violent thoughts. These are the men who are substantially higher in reactive aggression. There are also guys that are self-centered and narcissistic. They don't feel concern for others, don't really pursue long-term relationships and are manipulative and cunning. They'll screw someone over or even physically assault someone reflexively without much thought. These are the men who are substantially higher in predatory aggression.
All in all individual variation contributes substantially less to moral catastrophes than sociocultural influence with respect to the expression of predatory aggression and reactive aggression. For example, one person who is six standard deviations above the mean in predatory aggression might be the serial killer with a kill count of 100. That is an illustration of genetic overdetermination and it contributes to a substantial minority of severe instances of morally horrendous behavior.
Then you have something like the holocaust. Ordinary people participated in it and therefore we can reasonably assume that those people represent the median for aggression. Things like economics, indoctrination, strong sense of tribal affiliation, and bureaucratic genericism conjured an environment whereby suddenly there is a strong sociocultural incentive for an ordinary man to pour a cannister down a tube and choke a small naked child to death for upwards of twenty minutes as the capillaries in their lungs which is what happened in the gas chambers. His expression of predatory aggression therefore was substantially expanded due to cultural influence. He himself may have been typical or only slightly above average in predatory aggression and possibly even engaged in that behavior with reticence or disgust. A smaller example is prison. You have to prove you're a tough son of a bitch in order to survive. In evolutionary terms, you have to consciously modulate your expression of predatory aggression by hyping yourself up, acting in a macho way, being more crude, blunting your sense of emotional response around extreme violence, etc.
In this way the human species could be viewed as a dynamically entropic catastrophe. A tsunami or an earthquake. All it takes is the right combination of triggers for us to transform into the most bestial and callous entities imaginable and far surpassing the destructive capacity of any natural disaster. It isn't a problem with men, capitalism, politics, etc. The human person is a predator. They very well could have been as docile as a rabbit or some other species without these underlying mechanisms but we aren't. Anyone who contributes to this roiling wave of disaster is a monster and is engaging in the worst kind of cruelty.
Sources:
https://www.sciencedirect.com/topics/neuroscience/predatory-aggression
https://pmc.ncbi.nlm.nih.gov/articles/PMC4260506/
https://journals.copmadrid.org/apj/art/j.apj.2016.03.001