Their next closest relatives are the African lorisids, the pottos, false pottos, and angwantibos.
The group's closest relatives are the slender lorises of southern India and Sri Lanka.
They make poor pets that are difficult to care for, and often die from infection, blood loss, improper handling or inadequate nutrition.
Slow lorises (genus Nycticebus) are strepsirrhine primates and are related to other living lorisoids, such as slender lorises (Loris), pottos (Perodicticus), false pottos (Pseudopotto), angwantibos (Arctocebus), and galagos (family Galagidae), and to the lemurs of Madagascar.
Their only documented predators—apart from humans—include snakes, changeable hawk-eagles and orangutans, although cats, civets and sun bears are suspected.