Scientists have long explored the inner lives of animals. Primates, in particular, have inspired research suggesting they have human-like emotions.
In an effort to document some of these emotions, photographer Anne Berry has spent several years traveling to small zoos from Germany to South Africa to capture intimate portraits of primates living in captivity. 
Berry shared a number of the photos with us here, but you can check out the rest at her website or in her upcoming book for Northlight Press.