Observation of the spectrum of light scattered by solutions of biological macromolecules.

While human social memory lasts decades and tracks relationships, less is known about nonhuman ape long-term memory.We present evidence that both chimpanzees and bonobos recognize the faces of familiar conspecifics even after many years of ...Recognition and memory of familiar conspecifics provides the foundation for complex sociality and is vital to navigating an unpredictable social world Tibbetts and Dale, Trends Ecol. Evol. 22, 529–537 (2007). Human social memory incorporates content ...