He has published over 140 scientific articles in medical and anthropological journals[1] on the topics of co-sleeping, breastfeeding, evolutionary medicine, and SIDS, and is the author of several trade and academic books.
McKenna has stated that, when reading through existing parenting literature, he was surprised to see that it contradicted his years of research and training about the universal aspects of primate life, particularly when it came to feeding and sleeping arrangements.
[4] At the University of California, Irvine School of Medicine, his neurology research team pioneered the first behavioral and electro-physiological studies documenting differences between mothers and infants sleeping together and apart.
Using traditional anthropological and medical research techniques, the laboratory responds to myths and controversies to provide scholars, parents, and the news media with accurate scientific information on a variety of sleeping arrangements, including safe co-sleeping practices.
In 2014, McKenna and his colleague Lee T. Gettler coined the term "breastsleeping" to describe a type of co-sleeping between a breastfeeding mother and infant that occurs specifically in an environment free from proven risk factors.
[6] Drawing on the historic anthropological relationship between breastfeeding and infant sleep, breastsleeping is considered to be the safest form of bedsharing, practiced worldwide for all of human history.