ABSTRACT: The present article examines the nature and function of human agency within the conceptual model of triadic reciprocal causation. In analyzing the operation of human agency in this interactional causal structure, social cognitive theory accords a central role to cognitive, vicarious, self-reflective, and self-regulatory processes. The issues addressed concern the psychological mechanisms through which personal agency is exercised, the hierarchical structure of self-regulatory systems, eschewal of the dichotomous construal of self as agent and self as object, and the properties of a nondualistic but nonreductional conception of human agency. The relation of agent causality to the fundamental issues of freedom and determinism is also analyzed. The recent years have witnessed a resurgence of interest

conducted through the mass media. The differing roles of publicity in the fields of brand advertising and public health promotion are identified and discussed in the context of theories of behaviour change. A number of widely used micro level models of social persuasion are presented and the prior use of such models in the development of mass media campaigns is discussed. The discussion of successful public health campaigns conducted outside the field of road safety in Australia introduces the examination of key elements of mass media campaigns conducted in a public health setting. The type of appeal used (rational/emotional/fear), the use of supporting activities (such as enforcement or incentive) and the duration, intensity, timing and exposure of media placement are identified as key variables in the effectiveness of mass media campaigns. Two international meta-analyses examining the effectiveness of road safety mass media campaigns and a number of individual evaluations are used to assist in the identification of best practice in the field of road safety mass media campaigns. It is concluded that persuasive or emotional campaigns are more effective than rational or informational style campaigns. Furthermore, the use of theoretical models to guide campaign development,

ive Theory, Bandura (1986) wrote that individuals possess beliefs that enable them to exercise a measure of control over their thoughts, feelings, and actions, that "what people think, believe, and feel affects how they behave" (p. 25). These beliefs comprise a self system with symbolizing, forethinking, vicarious, self-regulatory, and self-reflective capabilities, and human behavior is the result of the interplay between this personal system and external sources of influence. In all, Bandura painted a portrait of human behavior and motivation in which the beliefs that people have about themselves are key elements. Social Cognitive Theory and Self-efficacy Bandura (1986) argued that self-referent thought mediates between knowledge and action and that the capability to self-reflect is the most distinctively human characteristic, for it permits individuals to evaluate their own experiences and thought processes. Through reflection and selfevaluation, individuals can alter their

Because of the influential role the mass media play in society, understanding the psychosocial mechanisms through which symbolic communication influences human thought, affect and action is of considerable import. Social cognitive theory provides an agentic conceptual framework within which to examine the determinants and mechanisms of such effects. Human behavior has often been explained in terms of unidirectional causation, in which behavior is shaped and controlled either by environmental influences or by internal dispositions. Social cognitive theory explains psychosocial functioning in terms of triadic reciprocal causation (Bandura, 1986). In this transactional view of self and society, personal factors in the form of cognitive, affective, and biological events; behavioral patterns; and environmental events all operate as interacting determinants that influence each other bidirectionally (Figure 1). Social cognitive theory is founded in an agentic perspective (Bandura, 1986; 2001a). People are self-organizing, proactive, self-reflecting, and self-regulating, not just reactive organisms shaped and shepherded by environmental events or inner forces. Human selfdevelopment, adaptation, and change are embedded in social systems. Therefore, personal agency operates within a broad network of sociostructural influences. In these agentic

phenomena. The author would like to thank Joseph Cote, the editor, and three anonymous reviewers for their valuable comments.