Yes.
When you deal with human minds, how could any scientific method be applicable? There's nothing more disorganized than the insides of our heads. If anyone was to find a corresponding Newton's law on motion and gravity in psychology, we'd undobtedly find it would only apply to one of the sexes, in a particular age group and income bracket of a certain religion, living in a subsection of a specific part of society (such as northern europe, for example).
Psychology's mostly about thinking and believing anyway, what's applicable to one person won't be to another. I don't see how that would be compatible with the general scientific method.