Can't be reduced

As some psychologists may believe that psychology will be reduced to biology, I do believe that this is impossible. The reason why I believe this is impossible is because in biology there are no ways to find out people's thoughts, feelings as well as personality, since this can only be found through theory. However, in biology, people tend to look at the facts in an experimental way. In order for psychology to be reduced to biology humans will need to know and understand things that are not measurable. Which makes me believe that this will not be possible.