Male Chile

Marmosets have personalities similar to humans, and exhibit a number of traits, including:

Social organization
Marmosets live in family units where parents breed and offspring help raise the young.

Consistent personality traits
Marmosets have consistent personality traits, such as some being fast to approach novelty, while others are more careful.
Social cognition and communication
Marmosets are among a few primates that pair bond and care for their young cooperatively, and exhibit social cognitive abilities like imitation.
Group-level similarity
Marmosets exhibit “group-personality”, meaning there is a group-level similarity in personality traits.
Boldness
Boldness is a personality trait that is more consistent across social and solitary conditions.
Learning
Bolder marmosets learn faster than shy ones.

Common Marmoset (Callithrix jacchus)
Marmosets are also highly intelligent and can get easily bored, so they need a complex stimulating environment. They are also known to scent-mark their surroundings, which can spread a pungent smell all over furniture