IMHO, people and justification for right/wrong behavior are more complicated than portrayed. I’ve met many people who wouldn’t think twice about lying, cheating, stealing to further their self interests. Those who do show a higher level of moral fiber, do so because they have ‘evolved’ to survive in a ‘civilized’ society (note in a stressful situation many would probably behave differently which is why we value those who act selflessly when most of our survival skill instincts kick in). In general though, our moral compass of cooperation and living by the golden rule is the means to ensuring acceptance, harmony, and personal progress in society.

When I say ‘evolved’ in reality I think this moral compass is a learned behavior. I know as a child I did and said and did many things that were wrong, hurtful, and morally unjustified that I (hopefully) wouldn’t do today. Why? Probably because I thought it furthered my short-term interests. People who are morally grounded are typically taught or eventually learn that even if there is a short-term gain to self-serving behavior, the lasting consequences far outweigh them. People who don’t learn this lesson tend to be more narcisstic and will justify and rationalize what you or I might consider immoral conduct.

Of course, the bigger issue is what is immoral? I think a lot of it is a really grey area. The puppy killer portrayed in your example is clearly portrayed in a negative light (killing for fun of it is hardly ever a justified action). Let’s take your example, and modify it a little. What if Bob, a renowned scientist, was close to finding a cure for cancer and was ‘sacrificing’ the puppies to achieve that goal? Or what if the puppies were born with a rare disorder that caused them excrutiating pain to the point where they couldn’t function, whined constantly, and were clearly suffering and Bob was merely putting them to sleep and out of their misery? What if Bob didn’t kill dogs at all, but instead hunted deer for sport and had a lease with a deer feeding stand. Every season he sits in his heated blind waiting for a deer to come to get bite and BLAM! Another one bites the dust.

Depending on your perspective, these above examples could be totally rationalized (Big Game Hunter), or clearly immoral (PETA enthusiast). That goes back to the learned behavior and values we have come to learn on our individual journey as human beings. Therefor, everyone’s compass is unique and varied in a very personal way.