The background of an individual will have a big influence on how they communicate.
In some cultures, eye contact is viewed as impolite or disrespectful in certain situations, such as between a father and daughter or a professor and student. Similarly, some cultures display emotion and feeling in their communication whilst others are more subdued.
An individual who has been brought up in a close, loving family with lots of affectionate touching may naturally hug everyone they meet, even when it would be considered socially inappropriate, whilst an individual that has been abused in the past may be timid or cower away from people in close proximity to them.
Education (or a lack thereof) can limit an individual’s ability to communicate. They may not be able to read or write and may have a limited vocabulary with which to express themselves.
If an individual is from a different country, their knowledge of the English language could be limited, making it difficult for them to communicate their needs.