HISTORICAL PRECEDENT Developmental psychophysiology is the study of behavior – physiology relations in infants and young children. Issues that are commonly studied by psychophysiologists with adult populations such as cognitive processing, cognition-emotion interactions, or responses to stress, may be examined in populations of young children as well. For example, utilizing age appropriate paradigms, interested researchers have investigated infant visual attention through the measurement of cardiac orienting (Field, 1979; Sameroff, Cashmore, & Dykes, 1973); others have examined infant discrimination of human faces by recording event-related potentials (de Haan & Nelson, 1997; Nelson & Collins, 1991, 1992; Parker et al., 2005). Such research has been quite valuable in revealing the links between physiological responses and behavior in infants and children of different ages. When multiple ages are utilized, such studies have also revealed age-related differences in physiology-behavior linkages (Richards, 1985, 1989). Developmental psychophysiology, however, may offer the greater promise of revealing the processes by which both physiology and behavior change together over time. Such an approach necessitates a three-tier investigation. First, there must be a description of age-related changes in behavioral performance and physiological response. Second, there must be an attempt to describe how the physiological system itself is developing and changing over time, often as a function of the stimuli that are being studied. Third, there should be some attempt at integration of physiology and behavior. An example of this approach may be seen in the study of infant memory for faces.