According to the biophilia hypothesis, humans have a fundamental tendency to affiliate with nature. If this hypothesis is true, large majorities of people should express a high level of nature-friendliness (a tendency to affiliate with nature), and this level should have low variability across cultures. We tested this proposition using the inter-culturally applicable Human and Nature (HaN) scale. We compare the outcomes from 12 previously published studies that applied the HaN scale on four continents and show that a high level of nature-friendliness was indeed detected in all countries. We also demonstrate that the cross-cultural variability of the nature-friendliness levels was as small as their within-culture variability. Jointly then, these 12 studies offer strong support for the biophilia hypothesis. We share implications that are valuable for policymaking as well as further theoretical development of human-nature relationship research, particularly around relational values with nature and ecological virtue ethics.