In Japan, as in North America, there is great concern over the increase in cases of senile dementia that accompanies population aging. Unlike North America, however, fear about senility is not primarily expressed in relation to pathological conditions like Alzheimer's Disease (AD). Instead, as people grow older, their concern focuses on a widely recognized category of decline in old age which, although symptomatically and conceptually overlapping with AD and other forms of senile dementia, is distinguished from unambiguously pathological conditions. This paper examines the meaning and experience of this condition, known as boke, and shows that senility in Japan is culturally constructed in a way distinct from the clinical biomedical construction of senility-as-pathology which has become increasingly the norm in North America. Boke is differentiated from AD or other disease-driven forms of dementia on the basis that people have some degree of agency in relation to its onset--through activity, particularly activity within the context of groups, it may be prevented or at least delayed. Agency in relation to the onset of senility makes room for the possibility that, as one grows older, one can continue to engage Japanese normative values that emphasize: (1) avoidance of burdening others, (2) constitution of self-identity within the framework of reciprocal obligations, and (3) the importance of doing (agency) for defining what it means to be human.
Finally, I suggest that for cross-cultural studies of aging, the interpretation of what is considered normal or abnormal aging needs to be linked to the shifting systems of signs and symbols through which people articulate meaning as they experience the aging process and the forms of functional change and decline that accompany that process. While from a clinical perspective it may be clear where the line is to be drawn between what is normal and what is pathological aging, from an emic or ethnomedical perspective the basis of what is considered normal or abnormal aging may not have a direct link to disease.
Keywords: Japan, Aging, Senile Dementia, Alzheimer's Disease, Ethnomedicine