Studies conducted in people from all over around the world have shown that amiable people are more aggressive towards other at multiple places such as streets, workplace or even public services. These people are might be treated with no respect at their houses, and that might be the cause of their aggressive attitude. I strongly believe that the reason for this problem is because of personal issues.
At first, we should consider that these people might have personal issues which cause this unfriendly behaviour towards others against others. Some people might be too stressed or depressed from school or from their job. For example, nowadays people are more and more under pressure in order to meet deadlines or in order to work more to be paid more to overcome the global crisis that Covid-19 has brought with which has affected the whole planet. Consequently, these people might not have time to do a hobby to relieve the stress and end really stressed and depressed.
Moreover, these people may have financial problems. For instance, they may feel depressed or stressed from their economics to be polite with you. At this stage, you could calm them and talk to them about their problem and consider some possible solutions to help them deal with their problem. By doing so, you could help this person to overcome his problem.
To conclude, aggressive behaviour can be a result of several factors which affect the person differently. I stand by the opinion that the main reason for these types of behaviours is the modern way of life. But, what can we do in order to help these affected people?