As I've explained elsewhere, the society we live in today strongly encourages people to reason meritocratically, and to embrace notions such as that someone's moral value depends on whether and how others view them. In extreme cases, this leads to people dismissing others and their needs wholesale (e.g. when they categorize those others as property, a pest or relic).
Marshall Rosenberg, Walter Wink, and Walter Kaufmann have made compelling cases that humans have to be actively taught both this general way of thinking, and that it's okay to employ violence to 'put people in their place,' or to realize a desired outcome. And Rosenberg in particular has also offered strong evidence that even though most people alive today reason this way, pretty much everyone values helping others without hurting them, meaning that we all have the same basic needs and moral psychology.
As Walter Wink has pointed out, violence is a tool that allows us to realize certain outcomes that seem desirable to us: to change either the person we inflict it on, or those around them, by 'making an example' of them. Resorting to violence as a matter of policy (as our current justice system does) presupposes that people willingly act badly, so that there's no point trying to change their thinking: all we can do is declare undesirable behaviors 'punishable offenses,' so that the 'bad people' will have 'reasons' to not do the thing. Yet, as Marshall Rosenberg has noted, if fostering lasting behavioral in people is our aim, then violence never works, because while people may comply, they lack intrinsic motivation to act differently. For that, we need to ask -- and care about -- why people choose to harm others, so that we can to try and show them ways to meet their own needs in ways that don't involve harm to others.*
As I've explained elsewhere, pretty much everyone is taught how to systematically devalue the equal needs of (at least some) others. By the time we reach adulthood, this 'skill', and the meritocratic moral logic that undergirds it, are deeply rooted. And while people differ greatly in how broadly they apply this logic, basically none of us are able to ignore the many distractions (skin color, nationality, gender, ethnicity, intellectual ability, wealth, mannerisms, religious affiliation, and so on) that we are taught to take into account when it comes to recognizing and valuing other people's needs. As such, hardly any of us are able to embody the kind of inclusiveness, egalitarianism and solidarity that most of us do see as the ideal (that we mostly fail to live up to in practice).
The questions I want to explore here are, first, how we apply this 'skill' in the context of our thinking about the other animals, second, how this affects our treatment of them, and third, how the fact that we allow ourselves to behave and think this way towards the other animals affects how we treat and view other humans.