What makes humans unique? This is probably one of the most fundamental and enduring questions of theories and research concerning human nature, dating at least as far back as Charles Darwin (Darwin, 1871/2008). One can approach this question, as many have, by documenting the differences between humans and other non-human animals, particularly our nearest evolutionary relatives. Humans have larger brains, symbolic thought, language, superior reasoning and planning abilities, teaching, and so on. Another approach to the question of human uniqueness is to identify reasons for why humans may have evolved such a specialised set of cognitive capacities. According to the cultural-intelligence hypothesis (Herrmann et al., 2007; van Schaik & Burkart, 2011), the answer lies in the complexity of human social lives. While most primates evolved social intelligence that enables efficient cooperation and competition with conspecifics, human social structures vastly exceed the scenarios of social interactions seen in any other species. For an individual to be able to participate in human culture, defined by its language, tools, traditions, and so on, one must possess a specialised set of social cognitive capacities. One such capacity is theory of mind.