One influential branch of psychology——focuses on human behavior in the context of how human beings relate to and influence one another.

Explanation:

The systematic study to understand the behaviour of humans and other animals is called behaviourism. The study of relation between our mind and our behaviour is called behaviourism. The scientist and researchers who studying behavioural psychology try to find patters in our behaviour and actions, they try to know why we behave the way we do.

It emerged in the early 1900s  as a reaction to other fields of psychology which were unable to make predictions that could be tested with experiments. Ian Pavlov was one of the first behavioural psychologists, he published the results of an experiment that he conducted on dogs.