^{Video created in our lab while exploring skin temperature changes in hugging couples with a forward looking infrared (FLIR) camera, that is, a camera that senses thermal infrared radiation.}

“We suggest that the understanding of abstract concepts like affection through concrete experiences such as physical warmth is often derived from specific affordances with which people have become equipped. People mark social relations through actual changes in bodily temperatures, possibly offering evolutionary advantages in early life stages.”