I think it has to do with how they themselves are treated. People are like dogs in many ways. If you lock them in a cage with inadequate space, abuse them regularly and throw a piece of meat into it at feeding time and let them have at it, they will go after each other and cower when you enter.
With few exceptions in history, University greeks, military personnel, corporate underlings, & etc, will espouse long and hard about unjust treatment and the need for change while they are on the bottom of the pecking order, but once in the position of authority, will rarely effect change.
Sociologists have written volumes on the brutality of the lower classes for the past 200 years; Malthus, Godwin, etc. I believe that their lives are more brutal for lack of resources and they behave accordingly. This is reflected in all classes to the degree proportionate to their deprivations, whether it be physical, psychological or emotional torment, perceived or real. Witness the brutality of the ghetto.
Even in the upper classes, literature is rife with examples of a noted lack of emotional support by parents, cohorts and the institutions they attend. This is reflected as a lack of compassion among their own. And pity those of classes outside one’s own, for they deserve even less.
On a grander scale, look at countries that experience a lack of basice resources such as potable water delivery systems and adequate food. You will never find the luxury of democracy in these social environments. Like Ghana, it is the man with the most guns who rules.
Take a hostile corporate office envirnment. All the cubicle denizens working diligently yet desperately, cowering to tyranical bosses, uncompassionate to their cohorts, afraid for their jobs as most are encumbered with enormous debt according to statistics.
The maxim is this: If you want people to act less like “animals,” treat them less like animals. This is an argument for good government and just and egalitarian judicial system.
Be the change you want to see in others. Be the exception.