What explains the amiable behavior sometimes observed between tamarins and long-term handlers in controlled research facilities?

Answer

Intensive, prolonged social bonding within small, structured groups

Apparent friendliness stems from the intensive, prolonged social bonding that occurs within the small, structured groups researchers work with.

What explains the amiable behavior sometimes observed between tamarins and long-term handlers in controlled research facilities?
behavioranimalMonkeyPrimatetamarin