I had a similar concern and was just emailing back and forth with AADSAS about this. I have my masters, so classifying classes as "non-science" vs. "other science" was a little confusing. Although I'm not sure about the penalty issue regarding entering course improperly, this is what I found out:
It seems like it depends only on the department the course was in. Not necessarily the title of the course. So, with your psychology example, any course within the psych department would be considered a "non-science." So if you contact AADSAS and ask them about specific departments you are unsure of, they will help you classify your coursework.
As a slight tangent:
For me (and hopefully this will help anyone else with their MPH), public health is considered a "non-science." However, that is only if you take a course in a public health department and does not apply to the entire degree. For those wondering:
Biostatistics Department courses = other science
Epidemiology department courses = non-science
Environmental health science department courses= other science.
Anyways, I guess it would be best to just know how to classify your courses beforehand? AADSAS is super fast at responding to emails.