 According to Hood, the introvertive mystical experience may be a common core to mysticism independent of both culture and person, forming the basis of a "perennial psychology".According to Hood, "the perennialist view has strong empirical support," since his scale yielded positive results across various cultures, stating that mystical experience as operationalized from Stace's criteria is identical across various samples.Although Stace's work on mysticism received a positive response, it has also been strongly criticised in the 1970s and 1980s, for its lack of methodological rigueur and its perennialist pre-assumptions.