gertrude weaver , 116 , of camden , arkansas , attributes her longevity to treating others well and exercising three times a week in her wheelchair .
with the death of 117-year-old misao okawa in japan on wednesday , weaver became the world 's oldest person , according to the los angeles-based gerontology research group .
the daughter of sharecroppers was born in arkansas near the texas border and worked as a domestic helper .