Recent PhD graduate Jason Bruck of the University of Chicago has performed the first systematic study to show multi-decade long-term memory in a non-human species. Dolphins have social memory for each other’s unique signature whistles for at least 20 years. Interestingly, kin and non-kin remembered equally well. Humans can remember photographs of faces for upwards of 47 years, but faces change. Dolphin whistles remain stable, meaning that this could be the longest recognition system in the world. This research sheds new light on the potential for long-term memory in non-human species and allows a better understanding of how complex social patterns may affect social memory.