I think that humans do tend to harm each other. I think that humans are innately sinful and selfish, this would mean that they tend to be hurtful towards humans. It does sound a bit pessimist but I believe it to be true. Granted that  this doesn't mean that everyone isn't always self-centered and mean, but its a natural tendency.
      For example, in a situation of life or death an individual will be more likely to be thinking of themselves than the person next to them. They will be concerned for their own safety and survival. Because people are naturally selfish that would be the most plausible response.
      So to sort of wrap it up I do think that humans tend to harm each other. This may not be their specific intent but because we are selfish we sometimes wind up hurting others because we are putting ourselves first.