These questions are considered the roots of a cognitive perspective of psychology. At the same time Hippocrates' observations of the brain controlling the rest of the body led to biological explainations. It wasn't until the late 19th century that psychology was introduced as scientific, with people believing that people's minds and behaviours could be observed and analysed through systematically and scientificly varying the situation presented to them. The biological perspective believes that all psychological events are as asreult of the activity of the brain and nervous system. It attributes overt behaviour to electrical and chemical events taking place in the body.
Researchers study the brain activity of animals to in turn understand the human brain.
It can give them an idea of how inborn biological mechanisms are responsible for human motives and emotions. Instead of studying the brain and nervous system, behavioural psychologists study the behaviour of individuals. John Watson, a psychologist in the early 1900's was the first behavioural psychologist. He stated that behaviour can be observed by other people. One critisicm of the strict behavioural approach is that it does not take into account the individuals mental processes and conscious experiences.e.g deciding, reasoning, problem solving.