Humans are an unusual species – our babies are born suprisingly helpless, with big consequences for childbirth and parenting, and growth and brain development. But in other ways, human babies are not quite as helpless as they first appear! Learn more about human helplessness below.
The infographics below were created in a 2022 University of Ottawa Directed Readings Course (PSY 4110) and draw on materials from the book Costly and Cute: Helpless Infants and Human Evolution (2016), edited by Wenda R. Trevathan and Karen R. Rosenberg.
Human helplessness and childbirth
Motherhood is demanding.
Human mothers face challenging childbirths relative to other primate species. For more, see Dunsworth, H. M. (2016). The obstetrical dilemma unraveled. In W. R. Trevathan and K. R. Rosenberg (Eds.). Costly and cute (pp. 29-50). School for Advanced Research Press. as well as E.A. Quinn Infancy by design and D. Falk Baby the trendsetter in the same volume. Infographic by Marija Bolic, used with permission.
Human helplessness and brain growth
The human brain grows a lot in the first year of life.
The human brain keeps developing into our 20s, but the majority of its adult size is reached in the first year of life, a period when human babies are highly dependent on others. For more, see DeSilva, J. M. (2016). Brains, birth, bipedalism, and the mosaic evolution of the helpess human infant. In W. R. Trevathan and K. R. Rosenberg (Eds.). Costly and cute (pp. 67-86). School for Advanced Research Press. Infographic by Liberty Alferis, used with permission.
Human helplessness compared to other mammals.
Humans babies are a different kind of helpless.
Human newborns are in some ways more similar to altricial species like cats or mice, but in other ways more like precocial species like horses. Overall, humans are helpless in a unique way! For more, see Trevathan, W. R. & Rosenberg, K. R. (2016). Human evolution and the helpless infant. In W. R. Trevathan and K. R. Rosenberg (Eds.). Costly and cute (pp. 1-28). School for Advanced Research Press. Infographic by Zoe Brown, used with permission.