The traditional view of human development states that development is:

The answer is There are few or no changes that occur during adulthood
According to the traditional view, Human's development is complete as soon as we enter adulthood,  both physically and mentally.
But recent studies show that even after entering adulthood, we still experience many developments in both through experience, relationship with other people, diet, etc.

Well, l think that some effective communication is, emotional barriers and lack of attention, interest distraction or irrelevance. also some physical disabilities such as hearing problems or speech difficulties.      l hope i am correct  and you good luck.