Pfefferle, D., Kazem, A. J. N., Brockhausen, R. R., Ruiz-Lambides, A., & Widdig, A. (2014). Monkeys spontaneously discriminate their unfamiliar paternal relatives under natural conditions using facial cues. Current Biology, 24(15), 1806-1810. doi:10.1016/j.cub.2014.06.058.