Read this guidebook that a state health department in Australia wrote to prevent their health professionals from making incorrect assumptions or decisions regarding their patients and coworkers.
As the manual states:
"Before you can begin to have insight into diverse communities, individuals and groups, you need to understand and know your own culture and identity, whether this is your personal ethnic, spiritual or cultural heritage or your professional or organizational affiliations. Evidence has shown that our attitudes, whether we are conscious of them or not, have a direct and significant impact on the people around us.
It is impossible to know all the different rules that might exist across different cultural groups. However, it is possible to approach your work with the understanding that different and complex cultural conventions exist, and to seek out these conventions in order to both improve understanding, to adapt to whatever cultural codes you encounter, and to avoid incorrectly attributing negative characteristics onto a particular group or person."