What would you say If someone cited the existence of evil people like those that set up fake investment opportunities & then keep the money or serial killers, as an argument against the idea that humans are naturally ethical?
I think the misconception probably comes from the media. There are hundreds of stories that talk about the poor choices people make. However you rarely hear about the people who make good choices on a daily basis.
Well, I would have to say that you are looking at the exception to prove the norm. The majority of individuals manage to abide by the rules of society and live ethically without deliberately breaking such regulations. There will always be some people who choose to live unethically and try to benefit themselves by breaking rules, but that does not mean to say that humanity is essentially unethical.
I would have to clarify the statement: Mentally and physically healthy humans are naturally ethical. Humans who are well-adjusted, eat well, excercise, get enough sleep, are able to be employed and socialize well with others, have the ability to pay their bills, and have interests in hobbies, etc. are naturally ethical. The humans mentioned in your examples probably have a mental illness or some socialogical flaw..ergo, they are not "healthy" in some respect.
You might get some interesting answers for this question if you post it in the discussion area.
To generalize that all people are a certain way because of a few might be a logical fallacy. There will always be exceptions to one particular way of life or a particular type of situation. not all people that work at a bank are thieves, but there will always be a small percentage of people that want to work at a bank to be in the best possible position to steal from the bank. That does not mean all employees are unethical.