Mood, Blood Pressure, and Heart Rate at Work: An Experience-Sampling Study Remus Ilies and Nikos Dimotakis Michigan State University David Watson University of Iowa We describe a study that examined the distinctiveness of momentary positive and negative affect (PA and NA) and their relationships with blood pressure and heart rate at work in a sample of 67 full-time employees who provided psychological and physiological measurements multiple times a day, over 10 working days. These employees recorded their subjective ratings on personal digital assistant devices programmed specifically for this study, and assessed their blood pressure and heart rate using automatic recording devices, at each measurement period. Results support the distinctiveness of PA and NA. First, within-individual factor analyses confirmed the existence of two underlying factors in the momentary affect ratings. Second, the within-individual correlations between PA and NA scores (.14), and among the two latent constructs (.13) were both low in magnitude. Finally, as predicted by theory, NA was significantly related to blood pressure within individuals, whereas PA and blood pressure were unrelated (both PA and NA were related to heart rate within individuals, as predicted). Keywords: affect, blood pressure, health More then two decades have passed since the publication of Watson and Tellegen’s (1985) seminal article proposing a “consensual” structural model of mood, and the simple opening sentence of that arti- cle, “Psychology has rediscovered affect” (p. 219), has reverberated in many areas of social science including applied, occupational, and health psychol- ogy. That is, Watson and Tellegen’s conceptual model considering positive affect (PA) and negative affect (NA) to be the “major dimensions of emotional experience” (p. 234) and the scales developed for measuring these dimensions (i.e., the Positive and Negative Affect Schedule, or PANAS; Watson, Clark, & Tellegen, 1988) have generated an enor- mous body of scientific research. For example, in little over two decades since its publication, the PA- NAS article (Watson et al., 1988) has been cited more than 4,500 times according to the Social Sci- ences Citation Index (as of 09/16/2009), of which more than 1,000 citations came from applied psy- chology or health-related publications (e.g., health care sciences and services, public, environmental and occupational health; neurosciences; cardiac and car- diovascular systems; etc.). Watson and Tellegen’s (1985) model posits that PA reflects the extent to which a person experiences a high-energy pleasant state and feels enthusiastic, active, and alert, whereas NA represents a dimension of subjective distress that is unpleasant and includes a variety of aversive mood states, including anger, guilt, and fear. More important, PA and NA are conceptualized as distinct dimensions of affective experience that represent the subjective components of two biobehavioral systems that underlie approach (the facilitation system) and withdrawal (the inhibi- tion system) behaviors (see Watson, Wiese, Vaidya, & Tellegen, 1999). Although the PA–NA model has proven extremely useful in several fields of investigation (see Watson, 2000), including organizational psychology (see Thoresen, Kaplan, Barsky, Warren, & de Chermont, 2003) and occupational health psychology (e.g., Schat, Kelloway, & Desmarais, 2005), positions on whether this model adequately represents emotional experience have been anything but consensual. More specifically, there has been continuing confusion and controversy over the basic premise of the PA–NA model that considers PA and NA to be distinct di- mensions of affective experience (see Diener, 1999); furthermore, the independence of the PANAS PA and NA scales has often been questioned (e.g., Green, Goldman, & Salovey, 1993). Given the popularity of Remus Ilies and Nikos Dimotakis, Department of Man- agement, Michigan State University; David Watson, De- partment of Psychology, University of Iowa. Correspondence concerning this article should be ad- dressed to Remus Ilies, Department of Management, NBC 475, Eli Broad Graduate School of Management, Michigan State University, East Lansing, MI 48824. E-mail: ilies@msu.edu Journal of Occupational Health Psychology 2010, Vol. 15, No. 2, 120 –130 © 2010 American Psychological Association 1076-8998/10/$12.00 DOI: 10.1037/a0018350 120