What Are Little Learners Made of? Sugar and Spice and All Things Nice, and Leptin and TNF α and Melatonin

Two articles in this special section introduce a set of hormones which have been shown, in basic research, to play a role in cognition and learning, but which have not as of yet reached the public eye and educators’ and policy-makers’ attention. A prior special section of this journal focused on stress hormones, and in particular the stress-sensitive hormone cortisol, and its potential role in learning (Blair, 2010; Bugental, Schwartz, & Lynch, 2010; Lisonbee, Pendry, Mize, & Gwynn, 2010; RappoltSchlichtmann & Watamura, 2010). While important, and a key focus of my own research (Adam, 2012), cortisol is only one of many circulating hormones that are influenced by children’s experience and behavior, and cross the blood–brain barrier to reach centers of the brain involved in regulation of mood, attention, alertness, and executive functioning and memory processes. Successful calibration and regulation of each of these aspects of neurobiology are increasingly being recognized as central to school readiness and successful learning (Blair, Granger, & Peters Razza, 2005). My title, a small twist on a 200-year-old nursery rhyme, is intended to imply that little learners are made of many things, and among them a much wider range of biological, and in particular hormonal factors than have previously been implicated. Child neurobiology, including aspects of neurobiology central to learning, is constantly being informed and sculpted by experience and by children’s engagement with their environments (Fischer, 2009; Nelson, 2000). One pathway by which experience is conveyed is by way of circulating hormones, which are in turn informed by our