Weakness - Introspection lacks validity
most psychs accept the claim we have very little knowledge of the causes of, and processes underlying our behaviour and attitudes, a claim that would challenge the value of introspective reports.
Particular problem in the study of implicit attitudes
e.g., a person may be implicitly racist, which influences the way they react to members of a different ethnic group, yet because such attitudes exist outside of conscious awareness, self-reports through introspection would not uncover them.
means Wundt's explanation lacks validity as the reports from ppts may not be accurate - not because they were being deliberately honest but because their real-life experiences may be unconscious