Becky Thompson calls herself a monkey mom. She has lived for six years with Kristi, a 22-year-old capuchin monkey trained to help her with everyday tasks she can no longer perform since a 1981 ...

A small monkey sits on a white countertop in a Boston training facility. With dexterous hands, the monkey—a capuchin, native to the forest canopies of Central and South America and known for its ...