The hominids are the members of the biological family Hominidae (the great apes), which includes humans, chimpanzees, gorillas, and orangutans.
The exact criteria for membership in the Homininae are not clear, but the subfamily generally includes those species which share more than 97% of their DNA with the modern human genome, and exhibit a capacity for language or for simple cultures beyond the family or band.
The theory of mind including such faculties as mental state attribution, empathy and even empathetic deception is a controversial criterion distinguishing the adult human alone among the hominids.
Humans acquire this capacity at about four and a half years of age, whereas it has neither been proven nor disproven that gorillas and chimpanzees develop a theory of mind.
This is also the case for some new world monkeys outside the family of great apes, as, for example, the capuchin monkeys.