Experienced fathers show a short latency to enter the infant’s cage and approach for all four stimuli: familiar infant (FI), unfamiliar infant (UI), familiar vocalization (FV), and unfamiliar vocalization (UV). Fathers had a significantly shorter latency than control males (inexperienced nonfathers). (Reprinted from Zahed SR, et al. Male parenting and response to infant stimuli in the common marmoset (Callithrix jacchus). American Journal of Primatology, 70:84–92. © 2008 John Wiley & Sons.).