Description: Years ago while sitting in a park watching a couple of my children play I saw a fascinating exchange. A small boy, about 3 years old, tripped getting off of a swing and did what looked like a quite painful face-plant onto the ground (no there was no pea gravel or shredded tires to cushion the blow). What I was amazed by was that the child leapt to his feet and rather than bursting into tears he looked around, zeroed in on his mother’s location (she was sitting on a bench facing away from the swings), and then ran up to his mother and tugged on her coat sleeve. As she turned and looked at him he burst into tears and though he did not make much noise his tears were flowing and he was indicating that his face hurt. What was going on became clear as his mother hugged him and then sat him on her lap and signed a series of questions and, likely, reassurances to him while examining his face closely and wiping his tears away. What amazed me was that the young child had clearly learned that verbal distress signals would not work with his deaf mother and he had adapted to another way of getting the parental support he needed. The cries of human infants are recognized as call for assistance by virtually any human and for most the cries pull on empathy strings that seem evolutionary selected to increase the likelihood that infants will get the help they need. Doubt this? Well think about the last time you heard a crying infant on a plane … it only become noxious when you cannot do anything about it and you cannot walk away from it (and you did not bring noise cancelling earphones). Think about how this adult response is triggered and think about whether it might even be active across species, and then read the article linked below to see what recent psychological research has to say about these questions.
Source: A Baby Wails, and the Adult World Comes Running, Natalie Angier, Basics, Science, New York Times.
Date: September 4, 2017
Photo Credit: Anita Kunz, New York Times
Links: Article Link — https://www.nytimes.com/2017/09/04/science/crying-babies-animals.html
So the drive to respond to infant cries is a rather powerful, and basic, thing. When infant mice are genetically altered so they cry without noise they are ignored entirely by their mothers (lucky for the child I talked about above human mothers are a bit more adaptable!). There are cross-species responses to infant cries (at least in Bambi’s mother!). Human parents early on seem to learn how to tell the difference between their infant’s cries, responding differently to the “I am boarded here in bed” cry as compared to the “OMG the cat is trying to kill me” cry. Researchers noted in the article linked above described the differences in infants’ reactions to fear, frustration and pain (note the fancy ethical footwork in getting this particular data point). Recent research is starting to show exactly how the human brain is wired to respond to the distress calls of dependent off spring, something that clearly has both individual and species survival value!
Questions for Discussion:
- Do human adults respond only the cries of their own infants?
- What might it be about infant cries that lead to even cross-species adult responses (hint: it may not be about the cries themselves)?
- If mouse pups that make no noise when distressed die of neglect how did the three year old I talked about at the start of this post with a deaf mother survive?
References (Read Further):
Lingle, S., & Riede, T. (2014). Deer mothers are sensitive to infant distress vocalizations of diverse mammalian species. The American Naturalist, 184(4), 510-522. http://www.journals.uchicago.edu/doi/full/10.1086/677677
Hernandez-Miranda, L. R., Ruffault, P. L., Bouvier, J. C., Murray, A. J., Morin-Surun, M. P., Zampieri, N., … & Fortin, G. (2017). Genetic identification of a hindbrain nucleus essential for innate vocalization. Proceedings of the National Academy of Sciences, 114(30), 8095-8100. http://www.pnas.org/content/114/30/8095.full
Parsons, C. E., Young, K. S., Joensson, M., Brattico, E., Hyam, J. A., Stein, A., … & Kringelbach, M. L. (2013). Ready for action: a role for the human midbrain in responding to infant vocalizations. Social cognitive and affective neuroscience, 9(7), 977-984. https://scholar.google.ca/scholar?output=instlink&q=info:2oXxJ7mo4lYJ:scholar.google.com/&hl=en&as_sdt=0,5&scillfp=15435527558104599162&oi=lle
Chóliz, M., Fernández-Abascal, E. G., & Martínez-Sánchez, F. (2012). Infant crying: pattern of weeping, recognition of emotion and affective reactions in observers. The Spanish journal of psychology, 15(3), 978-988. https://pdfs.semanticscholar.org/ee10/46ce0c4356ecd485ad4439441e7aa4993338.pdf
Sheinkopf, S. J., Righi, G., Marsit, C. J., & Lester, B. M. (2016). Methylation of the glucocorticoid receptor (NR3C1) in placenta is associated with infant cry acoustics. Frontiers in behavioral neuroscience, 10. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4889592/