How do people know or judge what is right or wrong and what is “common sense”? There are some things which, attributing right or wrong are relatively easy, for example, a person explaining something with appropriate and proven scientific theory. But in the real world, things are sometimes far more complicated than that specific example, people tend to overuse the word "common sense" and apply what they think is right or wrong in complicated situations too often.
To get an idea of complicated situations, consider this.
Imagine an overseas student from Asian background did something troublesome and was caught by a teacher grown up in Australia. The teacher might want the student to look them in the eye when the teacher explains to the student what the student did wrong, in some cases, the teacher might even want acknowledgement from the student. However due to difference in the culture where the student is grown up, the student might choose to not look at the teacher in the eye and falls to silence as an act to acknowledge his/her mistake.
If we understand the cultural values of both parties in this situation, we can understand it as that the teacher wants the student to listen to him/her when talking, and acknowledge the mistake the student has made. While the student paid respect to the teacher and knows he/she made a mistake. However due to the difference in the expectation and if both parties did not know what certain action meant for people from a different cultural background, some miscommunication might occur. Such as that the teacher might think the student is not listening to him/her because the student is not looking at the teacher in the eye when he/she is talking etc.
In the above example, if in the event that a miscommunication occurred, it is difficult, if one is to judge which party is right or which party is wrong. People observe and learn from their experience, these experiences and the cultural values in the environment they live in construct the people’s thinking and expectation, and this may be called “common sense”. The problem is that, if one relies on “common sense” too much, the chances of miscommunication and misunderstanding when interacting with people from different cultures increases.
Meta-ethics studies, as according to Richard Garner and Bernard Rosen, suggests that one of the three meta-ethics problem is "How may moral judgments be supported or defended?"; in other words, how do we know our judgements on moral issues are right or wrong? This suggests that there is no definitive true or false when people make judgements about right or wrong on moral issues (such as the above situation). This view suggests that, if we are to judge which party in the above situation to be right or wrong, we may be simply expressing our feelings and emotions towards the situation. This judgement, will be based on our views on past life experiences that will construct our thinking, and that the judgement itself also cannot be verified or falsified. It is problematic if we include morality in our "common sense" and make judgements on complicated moral issues when it is not verifiable knowledge (e.g. science which can be verified or falsified by evidence) because then, it is easy to create conflict and miscommunication with people from different culture even when none of the parties can be right or wrong.
That being said, can we ever expect a certain degree of “common sense” that applies to people from different culture? The answer is, yes, we can. Even if one is to take the extremes, say country A consist of tribal population with very limited knowledge in science, technology and medicine and country B with advanced knowledge in science, technology and medicine. Despite a lot of major differences in the live experience, a lot of similarity also applies, such as killing people with malicious intent are unlawful, care for the young, sick and disabled and respect for the elderly etc. Hence, there can be some common expectation and values which may apply to any person regardless of their difference. The interesting question to think about is why, despite such differences in lifestyle, experience and cultural values that some degree of similarity applies?
With the world becoming more and more interconnected and multiculturalism bringing people from all over the world together. Although it is difficult, and sometimes people simply forget, but we can reduce our miscommunication and conflicts; get to know people from other cultures; and we may learn valuable things from them if we can try to lower our expectations, think and try to understand our differences and respect each other.