Late Adulthoodyearsthatencompassage65and beyondotherdevelopmentalpsychologists further divide later adulthood into:youngold(ages 6585)oldold(ages 85 and beyond) stagesGerontology-or the study of old age and agingGerontologists-are particularly interested in confronting ageismAgeism! or pre"udice and discrimination against older adults! inevitably means physical decline#aylic$%s &ellular!&loc$ 'heorye(plainsthatcellulardivisionis related to agethereislessdivisionhappeningin middle and late adulthood basisforcalculatinglifespanacross species)placingushumansina *deadline* at +,- years of age .ne possible reason /hy cellular division slo/sdo/nas/eageisbecauseofthe progressivereductionof'elomeresthat serve as plugs that protect the tips or the ends of the chromosomes in the body .nepromisingthoughtofthetheoryis thepossibilityofarti0ciallyaltering cellular activity in order to raise life span1night%s 2ree 3adical 'heorye(plainsthatfreeradicals)unstable o(ygenmoleculesthatfreely4oatin thebody)damage56Aandother cellularstructures#istheory sho/edho/propernutritionand e(ercisecontributetoincreasinglife e(pectancy in humans7#89:&AL 5;