CHAPTER 1 Situations, Dispositions, and the Study of Social Behavior Mark R. Leary Rick H. Hoyle In a discipline with few propositions about which nearly everyone agrees, Lewin's (1936) dictum that behavior is a function of both the person and the situation enjoys widespread support. Even the most extreme psychodynamic or personological psychologist could not argue that situations exert no influence whatsoever on people's behaviors, nor could diehard behaviorists seriously deny that attributes within the person contribute to how he or she responds to situational influences. We find it hard to imagine that any contemporary behavioral scientist could seriously question Lewin's notion that thought, emotion, and behavior depend both on "the state of the person and at the same time on the environment, although their relative importance is different in different cases" (p. 12). Even so, debates have arisen regarding the relative influence of situational and dispositional variables on psychological processes, and researchers interested in the effects of situations and those interested in trait-like characteristics of the person have at times had an uneasy relationship with each other. Historically, this tension has been seen clearly in the relationship between social psychologists, who have traditionally stressed the impact of situational forces, and personality psychologists, who have focused on traits and processes operating within the individual's psyche. This rift was not apparent in the earliest years of scientific psychology. Wundt, Titch-ener, Terman, and other founders of the field considered the role of both situational and dispositional variables in their research. But the dominance of behaviorism during the middle part of the 20th century led mainstream research psychologists to focus on situational factors and, in extreme cases, to deny that intrapersonal factors play any role in behavior. At about the same time, the influence of psychodynamic approaches and the emergence of personality psychology as a separate field of investigation led other researchers to highlight intrapersonal variables. Indeed, although Gordon Allport (1937), the founder of scientific personality psychology, acknowledged the importance of both situations and personality, he also argued that personality and social psychology should be independent fields. As a result of these forces, social and personality psychologists worked largely in ignorance of each other's work and often at cross-purposes for over 50 years. Methodological Barriers Part of the schism was fueled by mere differences in intellectual interests, with social psychologists being interested in situations and personality psychologists in disposi- 3 4 I. INTRODUCTION tions and intrapsychic processes. But part of the rift also stemmed from differences in the prevailing research paradigms that dominated social and personality psychology during most of the 20th century. Social psychologists relied primarily on experimental methods in which participants were randomly assigned to experimental conditions that consisted of variations in the social situation. In fact, the classic experiments in social psychology—many of them conducted by founders of the field such as Asch, Sherif, Schachter, Festinger, and Milgram— exemplified the experimental approach and provided the dominant research paradigm for future generations of social psychologists that exists to this day. The social psychologists' reliance on experimental studies, typically conducted under controlled laboratory conditions, emerged not only from their inherent interest in situational influences on behavior but also from a philosophy of science that viewed experimental work as inherently more "scientific" than other research approaches. Because research that relied solely on descriptive or correlational methods, in which there is no random assignment of participants to conditions controlled by the researcher, was unable to draw firm conclusions about the causal relationships between purported antecedents and consequences, it was viewed as less rigorous, definitive, and thus "scientific" than research that employed true experiments. The experimentalists' perspective on the proper way to conduct psychological research led social psychologists to look askance at much of the research in personality psychology, which relied primarily on descriptive and correlational methods. The correlational tradition had a long and respected history from the earliest days of psychometrics and differential psychology in the early part of the 20th century. Galton, Pearson, Spearman, and others made contributions to the development of statistical methods that could be used to understand relationships among existing variables (e.g., correlation and factor analysis) and then used these methods to study individual differences in intellectual, psychological, and physical characteristics. But as social psychologists looked at results from correlational research, they saw mostly confounded variables and indefinite causal conclusions. Conversely, when personality psycholo- gists considered the research of their social-psychological colleagues, they suspected that the effects of any particular experimental treatment were rarely, if ever, obtained on every participant in the experiment. The findings in social psychology were based on comparisons of the means of participants' responses in various experimental conditions, and such comparisons obscured the fact that participants in a particular condition differed among themselves in how they responded to the independent variable. Because social psychologists were interested primarily in between-group situational effects, these individual differences were relegated to the error term of their statistical tests—with no effort to determine why some people reacted differently to the independent variable than others. When Lee Cronbach gave his presidential address to the American Psychological Association in 1957, he addressed this entrenched schism between researchers who rely on experimental versus correlational approaches. Cronbach observed that the field of psychology had fractured into two distinct disciplines—one defined by the experimental method and the other defined by correlational approaches. Furthermore, he noted that psychology was severely "limited by the dedication of its investigators to one or the other method of inquiry rather than to scientific psychology as a whole" (1957, p. 671), even though the primary difference between those who subscribe to each of these "two disciplines of scientific psychology" merely concerned whether the variability that they sought to explain preexists in the world or is created through experimental manipulations. The Person-Situation Debate Differences in scientific approach were accompanied by lively debates regarding the relative importance of situational versus dispositional factors in understanding behavior. Although a foreshadowing of this controversy can be seen earlier (Ichheisser, 1943), the opening volley was fired in Mis-chel's (1968) critique of the trait concept (and of personality psychology more generally). After critically reviewing 50 years of research that showed only small correlations in people's behaviors across situations and 1. Situations, Dispositions, and the Study of Social Behavior 5 time, Mischel concluded that "highly generalized behavioral consistencies have not been demonstrated and the concept of personality traits as broad response dispositions is thus untenable" (p. 145). His recommendation that psychologists abandon their efforts to explain behavior with traits and focus instead on situations was embraced by many social psychologists. For example, after posing a scenario asking the reader to predict whether a hypothetical person, John, will help someone he sees slumped in a doorway, Ross and Nisbett (1991) concluded: A half century of research has taught us that in this situation, and in most other novel situations, one cannot predict with any accuracy how particular people will behave. At least one cannot do so using information about an individual's personal dispositions or even about that individual's past behavior.... While knowledge about John is of surprisingly little value in predicting whether he will help the person slumped in the doorway, details concerning the specifics of the situation would be invaluable, (pp. 2-3, emphasis added) The effects of Mischel's (1968) book were powerful and immediate. For example, the percentage of articles published in the Journal of Personality and Social Psychology (JPSP) that included any reference to individual differences, whether alone or in combination with experimental manipulations, dropped from 50% to about 30% from 1966 to 1977 (Swann & Seyle, 2005). During the same time period, the percentage of articles in JPSP that reported purely experimental studies rose from about 50% to nearly 70%. At the same time, a great deal of time, energy, and ink were devoted to analyzing Mischel's (1968) claims more deeply. This discussion led to four important conclusions about the respective influences of situational and dispositional factors and the relationships among them (for overviews, see Bern & Funder, 1978; Cervone, Caldwell, & Orom, in press; Epstein & O'Brien, 1985; Kenrick & Dantchik, 1983; Magnusson & Endler, 1977; Snyder & Ickes, 1985). First, Mischel's (1968) most damning argument was that correlations between measures of personality and of behavior (and between measures of behavior collected on different occasions) typically hover around .30, seeming to reflect a very weak relationship. However, evidence emerged that the strength of situational effects on behavior were comparably low. In an early documentation of this point, Funder and Ozer (1983) calculated the correlation effect sizes for some well-known situational effects in social psychology (including classic studies of forced compliance, bystander intervention, and obedience) and found that all fell under .40. Other researchers have documented the same conclusion, suggesting that the strength of the relationships between measured dispositions and behavior are comparable to those between situational manipulations and behavior. Second, Epstein (1979, 1983) noted that a single measure of behavior is not a reliable indicator of a person's general behavioral tendencies. As a result, the magnitude of correlations between measures of personality and specific behaviors are attenuated by measurement error, which lowers the strength of statistical effects. When behaviors are aggregated across situations (just as self-report responses are aggregated across the items on a personality questionnaire), behavioral measures are more reliable, correlations are notably larger, and personality does a better job of predicting behavior. Third, research began to show that personality relates more strongly to behavior in some situations than in others. In "strong" situations that constrain people's behavior and provide clear cues regarding how people should behave, most people tend to act similarly. In contrast, when "weak," unstructured, or novel situations offer few cues or norms to guide behavior, large individual differences emerge (Caspi & Moffitt, 1993; Ickes, 1982). Importantly, the laboratory situations that researchers create to study individual differences typically constrain behavior (and thus the manifestation of traits) because they are rigidly controlled, often with independent variables that are intentionally designed to exert a strong influence on people's behavior. Even when situations are strong, however, we often still see individual differences. Even in experiments with powerful manipulations, such as Milgram's (1963) studies of obedience to authority, large individual differences in the degree to which participants disobeyed the experimenter were observed (Packer, 2008). Fourth, theorists noted a fallacy in the reasoning of those, including Mischel (1968), who used small personality-behavior corre- 6 I. INTRODUCTION lations to argue that situational factors play a more powerful role in behavior than personality. They noted that the fact that personality and behavior tend to correlate .30 does not indicate that any of the remaining variance is produced by the situation. Perhaps more important, they pointed out that the strength of situational and dispositional effects are not inversely related to one another, as one might assume. Contrary to first appearances, behavior can simultaneously be strongly affected by situational factors and also demonstrate strong evidence of individual differences. An example may help to make this point. Imagine that we administer a measure of dispositional fearfulness—the degree to which people tend to feel anxious and afraid—to a sample of 100 participants. We then randomly assign them to either an experimental condition in which they are threatened with painful electric shocks or to a control condition in which no threat is present and ask them to rate how anxious they feel. An analysis of the between-group differences in anxiety would undoubtedly show a very strong effect of experimental condition indicating that participants who were threatened with shocks reported more anxiety on average than those who were not. At the same time, however, correlating participants' pretest fearfulness scores with their anxiety ratings (whether correlated within each condition or for the entire sample) would undoubtedly reveal a large correlation between dispositional fearfulness and how much anxiety participants reported while they waited to be shocked. In such a case, a strong situational effect is revealed via between-group differences in state anxiety, and a strong personality effect is revealed via correlations between a measure of personality and state anxiety. Funder (2006) demonstrated this effect empirically. Using data from Funder and Colvin (1991), he showed that, across 62 behaviors that were measured across two situations, 20 behaviors differed significantly between the two situations at the same time that 37 behaviors showed significant within-person stability. Furthermore, the correlation between the magnitude of between-situation differences and cross-situational stability in behavior was -.01, showing that the relationship between situational influ- ences and behavior was independent of the relationship between personality influences and behavior. Fleeson (2001, 2004) similarly showed that strong cross-situational consistencies in people's modal or typical level of a trait are, at the same time, accompanied by large variability in their reactions across different situations. Considerations such as these not only helped to lead personality psychologists out of their crisis of confidence but also induced many social psychologists to consider personality more seriously in their own work. By the mid-1980s, the percentage of articles in JPSP that involved personality had regained their precrisis levels. In 2002, the last year for which data are available, just over half of the articles in JPSP included some measure of personality (Swann & Selye, 2005). Uses of Personality Variables in Behavioral Research Most social psychologists now acknowledge that dispositional factors predict variation in people's thoughts, feelings, and behaviors that cannot be explained by situational factors and that a consideration of personality can thus contribute to our understanding of social-psychological phenomena. Researchers differ in the degree to which they incorporate personality variables into their own work, but, overall, social psychology is more amenable to the study of personality than ever before (Swann &c Selye, 2005). Specifically, individual-difference variables can be used to address five basic types of questions about social thought, emotion, and behavior. Main Effects The simplest and most straightforward questions about the relationship between personality and social behavior involve "main effect" relationships between a particular disposition and some socially relevant thought, emotion, or behavior. In its simplest form, these kinds of studies simply correlate trait measures of personality with measures of particular behaviors, cognitions, emotions, or physiological reactions. For example, in a study designed to understand aspects of political behavior, Bizer 1. Situations, Dispositions, and the Study of Social Behavior 7 and colleagues (2004) found that individual differences in the need to evaluate—the tendency to chronically evaluate aspects of one's life and environment—predicted the degree to which people relied on party identification to form attitudes toward political candidates, the likelihood of voting in national and state elections, and the degree to which participants had emotional reactions to political candidates. Main-effect findings such as these show how features of people's personalities relate to social-psychological phenomena. Another strain of main-effect research involves correlations between two or more personality characteristics that are relevant to social behavior. For example, in a study that focused on the question of whether individual differences in religiosity are distinct from individual differences in spirituality, Saucier and Skrzypinska (2006) found that individual differences in subjective spirituality were positively correlated with private self-consciousness and absorption, but traditional religiousness was not. In contrast, traditional religiousness correlated with right-wing authoritarianism, but subjective spirituality did not. In studies such as these, relationships among various individual-difference measures that are relevant to social-psychological phenomena are examined. Much of the research that has been conducted on gender differences also falls in this category. Although not a "personality" attribute per se, gender is certainly a potent individual-difference variable that relates to a wide array of socially relevant thoughts, emotions, and behaviors (see Wood & Eagly, Chapter 8, this volume). The wealth of data regarding how women and men differ is reflected in the growing number of meta-analyses that have examined gender differences in aggression, leadership, communication, jealousy, conversational interruptions, and other interpersonal behaviors (e.g., Eagly & Johnson, 1990; Harris, 2003; Hyde, 1984). Of course, these main-effect analyses of the relationship between personality and socially relevant outcomes can become much more complex as researchers investigate multiple predictors of various outcomes, examine possible interactions among individual-difference variables in predicting behavior, and test me-diational and path-analytic models. Testing Theories about Situations The fact that a particular experimental manipulation influences some behavior of interest often does not provide a great deal of insight into the causes of the obtained effect. Even when the experiment was designed to test a particular theory, obtaining results consistent with hypotheses does not unequivocally support the theory's explanation, because one cannot prove the antecedent of a logical argument (the theory-based predictions) by affirming the consequent (obtaining results that support the hypothesis). Results may appear to support a hypothesis for reasons other than those that the theory specifies, and science is filled with examples of empirical findings that appeared to support a theory that was eventually shown to be false (Wallach & Wallach, 1998). One strategy for exploring the possible mechanisms underlying a particular experimental effect involves determining whether a particular personality variable moderates the effects of an experimental manipulation in the manner predicted by theory. In such instances, the researcher is not primarily interested in the personality variable per se but uses it as a methodological tool to test a hypothesis regarding a situational effect. Imagine, for example, that we are testing the hypothesis that a particular situational effect on behavior is caused by the fact that the situation increases people's concerns about being rejected by other people. If, prior to manipulating the independent variable(s) of interest, we obtain participants' scores on a dispositional measure of rejection sensitivity (Downey & Feldman, 1996), we can examine whether people who score low versus high in rejection sensitivity respond differently to the experimental manipulation, as they would be expected to do if the effect somehow involves concerns with rejection. Testing Theories about Dispositions A parallel strategy may be used to test hypotheses about the nature of a particular personality disposition. Historically, personality researchers have been interested primarily in main-effect hypotheses about dispositions, which they have tested by correlating scores on a personality scale with other scales or by comparing how people 8 I. INTRODUCTION who score low versus high on the scale behave in some situation. However, our understanding of the cognitive, emotional, or behavioral features of a personality variable can be enhanced by studying how people who score differently on the personality variable respond across various experimentally created situations. For example, to examine how optimists versus pessimists process negative emotional stimuli differently, Isaacowitz (2005) had participants complete a self-report measure of optimism. Participants then viewed three types of visual stimuli while their eye movements were tracked. Optimists showed selective inattention to the most negative stimuli, and this relationship remained significant after controlling for the effects of neuroti-cism, anxiety, and other variables. In studies such as this, experimentally manipulating features of the participants' environment (in this case the nature of visual stimuli) provides insight into the nature of the personality variable of interest. The strategy of combining manipulated independent variables and measured personality variables in a single study may result in precisely the same research design whether one is primarily interested in understanding the situational or the dispositional effects. In both cases, one is interested in the interaction of the experimental manipulation and the measured trait, and whether we say that the personality variable moderated the effects of the independent variable or the independent variable moderated the effects of the personality variable depends on our focus. State and Trait Convergence Certain situational variables create differences in people's psychological states that are conceptually analogous to the individual differences that we see among people who possess different levels of a personality trait. For example, just as mildly versus severely threatening situations elicit different levels of state anxiety, trait-like differences exist in the degree to which people are generally anxious. Likewise, certain situations increase people's motivation to obtain social approval, and certain people are disposition-ally more motivated to obtain approval than are others. When conceptually analogous states and traits exist, much can be learned by examin- ing similarities and differences in how low versus high levels of the state and low versus high levels of the trait manifest in thoughts, emotions, behaviors, or physiological reactions. For example, we can learn a great deal about anxiety both by assessing people's reactions to experimentally manipulated low and high threat and by comparing the reactions of people who score low versus high on a measure of trait anxiety. Similarly, we can study the relationship between the motive to obtain social approval and some behavior, either by experimentally varying factors that influence the desire for approval or by measuring individual differences in the need for approval. When the results of experimental studies of states converge with those of correlational studies of traits, we have greater confidence that we understand the processes involved. And, when they do not converge (and they often do not), interesting questions arise regarding why the state and trait operational definitions of seemingly analogous constructs are not equivalent. State-by-Trait Interactions Most social psychologists realize that, because people differ in their reactions to social stimuli, almost every general statement about the effects of a particular situational factor is at best incomplete and at worst misleading or wrong. Likewise, personality psychologists seem to understand that, although general predictions can be made on the basis of a person's position on a particular trait dimension, how people actually behave at any moment is typically influenced to some degree by the situation in which they are found. Thus explaining virtually any thought, emotion, or behavior at a given moment in time requires attention to both situational and dispositional factors. Furthermore, situational and dispositional factors not only exert separate, additive influences on people's responses but also can potentially interact in a statistical sense in that the effects of a particular situation may vary across levels of a trait or the effects of a trait may vary across situations. In fact, a particular trait may relate to behavior in only some situations, and a particular situation may influence the reactions of only people with a certain personality characteristic (Bern & Funder, 1978). Thus many studies 1. Situations, Dispositions, and the Study of Social Behavior 9 in social and personality psychology test for person-situation (or trait-by-state) interactions. Behavioral researchers tend to love statistical interactions, which, for some reason, tend to connote the presence of a more sophisticated and elegant psychological process than the mere presence of simultaneous main effects. Yet, although interactions between situations and dispositions are often interesting and informative, they are also notoriously difficult to obtain, and, when they occur, they tend to be quite small relative to main effects (Chaplin, 1997; Kep-pel, 1982). Several factors contribute to the weakness of person-situation interactions. First, the reliability of an interaction term is almost always lower than the reliability of its constituents (Bohrnstedt & Marwell, 1977). Because the strength of a statistical effect is attenuated by measurement error, the lower reliability of interaction terms decreases the likelihood that interactions will be detected even if they are present (McClelland & Judd, 1993). Furthermore, statistical models that include interaction terms have lower degrees of freedom for the error term than models that contain main effects only, so that statistical significance is less likely. We would add to these documented considerations the possibility that we live in a predominantly main-effect world. Although people undoubtedly respond differently from each other in any particular situation, those differences are often scaled similarly across situations. Thus, rather than finding interactions in which the effects of a situation are different for some people than for others, we often find two main effects that reveal a situational influence that increases or decreases everyone's reactions while the variability among people remains constant. In any case, for these and other reasons, statistical interactions between situations and personality are relatively rare relative to main effects, and those that do occur generally account for relatively little variance. Personality and situational influences can combine, influence, and interact with one another in much more complicated ways than through simple statistical interactions between experimental manipulations and measured personality variables. Proponents of "interactionism" point to the fact that situational and personality influences are mutually interdependent (Endler, 1983; Endler & Magnusson, 1976; Endler & Parker, 1992). The two sets of influences not only combine to influence or predict behavioral outcomes as just described, but they also influence one another in a dynamic, reciprocal fashion. In dynamic interactionism (Endler, 1983), the distinction between antecedents and consequences (and independent and dependent variables) may not be appropriate because situations and traits mutually influence one another in a variety of ways. For example, a person's traits can change the nature of a situation, such as when a highly agreeable person creates a friendly and cooperative social environment or an aggressive child instigates widespread hostility on a previously peaceful playground. Furthermore, people with different personality predispositions sometimes choose different kinds of social settings (Snyder & Ickes, 1985). Unlike in experimental settings in which people are thrust into situations that they did not pick, in everyday life people have a certain degree of flexibility and freedom to gravitate toward situations that are consistent with their personalities. Once people are in those self-selected situations, one finds it meaningless to ask whether their behavior is a function of the situations or of their personalities, because personality has determined the situation. Likewise, personality traits can change when people are in certain situations. For instance, the classic Bennington study showed that students became less conservative during their college experience and remained less conservative for years afterward (New-comb, Koenig, Flacks, & Warwick, 1967). Fortunately, the development of structural equation modeling and related statistical modeling strategies provides for the first time a way to approach modeling these complex, reciprocal influences. As described by Hoyle and Leary (Chapter 2, this volume), if data are gathered strategically (i.e., repeatedly, with appropriate spacing, across time and situations), it is possible to model the strong, dynamic version of interactionism that its proponents advocate (Endler & Parker, 1992). Nonlinearity A relatively uncharted direction for research on the interplay of personality and social behavior is the modeling of nonlinear relations. Following up on our suggestion that, 10 I. INTRODUCTION for the most part, people inhabit a main-effect world, we suspect that the relationships between variables in that world are, by and large, linear. However, just as interaction effects add nuance (and sometimes significant variance accounted for) to models of personality and social behavior, the addition of nonlinear terms to statistical models may add richness and subtlety to our understanding of the relationship between dispositions and behavior. Nonlinear relations can range from relatively straightforward curvilinear effects evaluated using power polynomials in multiple regression and trend analysis in analysis of variance to complex dynamical systems that attempt to model the "chaos" and "catastrophe" evident in human social behavior (e.g., Tesser & Achee, 1994; Vallacher, Nowak, & Kaufman, 1994). An example of work in which potential curvilinear relations are explored is Jorm and Christensen's (2004) study of the relations between religiosity and Eysenck's three-factor model of personality. In addition to a modest linear relation with one factor, they found quadratic relations with all three factors, indicating similarity in the personalities of individuals at the highest and lowest levels of religiosity. Tesser and Achee (1994) identified a number of instances of catastrophe in the prediction of social behaviors. In such cases, a seemingly linear relation between two variables quickly changes direction at a particular point before returning to a linear form like that before the "catastrophe." Such dynamical systems analyses also offer a compelling means of connecting seemingly disparate levels of analysis, such as neurobiology and personality (Mandell & Selz, 1995). Such findings contribute to conceptual models that offer more precise and nuanced accounts of individual differences in social behavior. Conclusions We find it difficult to imagine scientists in any other discipline falling into a controversy that would be equivalent to the traditional schism between social and personality psychologists. Would one branch of physics declare that the most important topics in the field involved the nature of matter but that forces such as gravitation were unimport- ant, while another branch declared that only the forces that acted on matter were worth studying (and that those forces could be studied without reference to the characteristics of matter itself)? Can we imagine one group of chemists being interested only in chemical structure and another group being interested only in interactions among chemicals without considering the structure of the constituents? Could meteorologists function if some studied only the properties of relatively static weather systems and others studied only the forces that act on them? Fortunately, most behavioral scientists now agree that the rift between social psychologists and personality psychologists has been misguided and detrimental to a full understanding of socially relevant thought, emotion, and behavior. This rapprochement does not mean that we should all start studying precisely the same things, of course. We need specialists in personality structure and process, as well as those who specialize in studying the effects of the "actual, imagined, or implied presence of others" (Allport, 1968, p. 3). But, in trying to understand the phenomena that constitute the science of human psychology, devoting attention to both situational and dispositional factors is the optimal strategy. References Allport, G. W. (1937). Personality: A psychological interpretation. New York: Holt, Rinehart & Winston. Allport, G. W. (1968). The historical background of modern social psychology. In G. Lindzey & E. Aronson (Eds.), Handbook of social psychology (Vol. 1, 2nd ed., pp. 1-80). Reading, MA: Addison-Wesley. Bern, D., & Funder, D. (1978). Predicting more of the people more of the time: Assessing the personality of situations. Psychological Review, 85, 485-501. Bizer, G. Y., Krosnick, J. A., Holbrook, A. L., Wheeler, S. C., Rucker, D. D., & Petty, R. E. (2004). The impact of personality on cognitive, behavioral, and affective political processes: The effects of need to evaluate. Journal of Personality, 72, 995-1027. Bohrnstedt, G. W., & Marwell, G. (1977). The reliability of products of two random variables. In K. F. Schussler (Ed.), Sociological methodology: 1978 (pp. 254-273). San Francisco: Jossey-Bass. Caspi, A., & Moffitt, T. E. (1993). When do individual differences matter?: A paradoxical theory of personality coherence. Psychological Inquiry, 4, 247-271. Cervone, D., Caldwell, T. L., & Orom, H. (in press). Beyond person and situation effects: Intraindividu-al personality architecture and its implications for the study of personality and social behavior. In F. 1. Situations, Dispositions, and the Study of Social Behavior 11 Rhodewalt (Ed.), Frontiers of social psychology: Personality and social behavior. New York: Psychology Press. Chaplin, W. F. (1997). Personality, interactive relations, and applied psychology. In R. Hogan, J. Johnson, & Briggs, S. (Eds.), Handbook of personality psychology (pp. 873-890). San Diego, CA: Academic Press. Cronbach, L. J. (1957). The two disciplines of scientific psychology. American Psychologist, 12, 671-684. Downey, G., & Feldman, S. I. (1996). Implications of rejection sensitivity for intimate relationships. Journal of Personality and Social Psychology, 70, 1327-1343. Eagly, A. H., & Johnson, B. T. (1990). Gender and leadership style: A meta-analysis. Psychological Bulletin, 108, 233-256. Endler, N. S. (1983). Interactionism: A personality model, but not yet a theory. In M. M. Page (Ed.), Nebraska Symposium on Motivation 1982: Personality—Current theory and research (pp. 155-200). Lincoln: University of Nebraska Press. Endler, N. S., & Magnusson, D. (1976). Toward an interactional psychology of personality. Psychological Bulletin, 83, 956-974. Endler, N. S., & Parker, J. D. A. (1992). Interactionism revisited: Reflections on the continuing crisis in the personality area. European Journal of Personality, 6, 177-198. Epstein, S. (1979). The stability of behavior: I. On predicting most of the people much of the time. Journal of Personality and Social Psychology, 37, 1097-1126. Epstein, S. (1983). Aggregation and beyond: Some basic issues on the prediction of behavior. Journal of Personality, 51, 360-392. Epstein, S., & O'Brien, E. J. (1985). The person-situation debate in historical and current perspective. Psychological Bulletin, 98, 513-537. Fleeson, W. (2001). Towards a structure- and process-integrated view of personality: Traits as density distributions of states. Journal of Personality and Social Psychology, 80, 1011-1027. Fleeson, W. (2004). Moving personality beyond the person-situation debate: The challenge and opportunity of within-person variability. Current Directions in Psychological Science, 13, 83-87. Funder, D. C. (2006). Towards a resolution of the personality triad: Persons, situations, and behaviors. Journal of Research in Personality, 40, 21-34. Funder, D. C., & Colvin, C. R. (1991). Explorations in behavioral consistency: Properties of persons, situations and behaviors. Journal of Personality and Social Psychology, 52, 773-794. Funder, D. C., & Ozer, D. J. (1983). Behavior as a function of the situation. Journal of Personality and Social Psychology, 44, 107-112. Harris, C. R. (2003). A review of sex differences in sexual jealousy, including self-report data, psychophysiological responses, interpersonal violence, and morbid jealousy. Personality and Social Psychology Review, 7, 102-128. Hyde, J. S. (1984). How large are gender differences in aggression?: A developmental meta-analysis. Developmental Psychology, 20, 722-736. Ichheisser, G. (1943). Misinterpretations of personality in everyday life and the psychologist's frame of reference. Character and Personality, 12, 145-160. Ickes, W. (1982). A basic paradigm for the study of personality, roles, and social behavior. In W. Ickes & E. Knowles (Eds.), Personality, roles, and social behavior (pp. 305-331). New York: Springer-Verlag. Isaacowitz, D. M. (2005). The gaze of the optimist. Personality and Social Psychology Bulletin, 31, 407-415. Jorm, A. F., & Christensen, H. (2004). Religiosity and personality: Evidence for nonlinear associations. Personality and Individual Differences, 36, 1433-1441. Kenrick, D. T, & Dantchik, A. (1983). Interactionism, idiographics, and the social psychological invasion of personality. Journal of Personality, 51, 286-307. Keppel, G. (1982). Design and analysis: A researcher's handbook (2nd ed.). Englewood Cliffs, NJ: Prentice-Hall. Lewin, K. (1936). Principles of topological psychology. New York: McGraw-Hill. Magnusson, D., & Endler, N. S. (1977). Interactional psychology: Present status and future propsects. In D. Magnusson & N. S. Endler (Eds.), Personality at the crossroads: Current issues in trait psychology (pp. 3-35). Hillsdale, NJ: Erlbaum. Mandeli, A. J., & Selz, K. A. (1995). Nonlinear dynamical patterns as personality theory for neurobiology and psychiatry. Psychiatry, 58, 371-390. McClelland, G. H., & Judd, C. M. (1993). Statistical difficulties of detecting interactions and moderator effects. Psychological Bulletin, 114, 376-389. Milgram, S. (1963). Behavioral study of obedience. Journal of Abnormal and Social Psychology, 67, 371-378. Mischel, W. (1968). Personality and assessment. New York: Wiley. Newcomb, T. M., Koenig, K. E., Flacks, R., & Warwick, D. P. (1967). Persistence and change. New York: Wiley. Packer, D. J. (2008). Identifying systematic disobedience in Milgram's obedience experiments. Perspectives on Psychological Science, 3, 301-308. Ross, L., & Nisbett, R. E. (1991). The person and the situation. New York: McGraw-Hill. Saucier, G., & Skrzypiňska, K. (2006). Spiritual but not religious?: Evidence for two independent dispositions. Journal of Personality, 74, 1257-1292. Snyder, M., & Ickes, W. (1985). Personality and social behavior. In G. Lindzey & E. Aronson (Eds.), Handbook of social psychology (3rd ed., pp. 883-947). New York: Random House. Swann, W. B., Jr., & Seyle, C. (2005). Personality psychology's comeback and its emerging symbiosis with social psychology. Personality and Social Psychology Bulletin, 31,155-165. Lesser, A., & Achee, J. (1994). Aggression, love, conformity, and other social psychological catastrophes. In R. R. Vallacher & A. Nowak (Eds.), Dynamical systems in social psychology (pp. 96-109). San Diego, CA: Academic Press. Vallacher, R., Nowak, A., & Kaufman, J. (1994). Intrinsic dynamics of social judgment. Journal of Personality and Social Psychology, 67, 20-34. Wallach, M. A., & Wallach, L. (1998). When experiments serve little purpose: Misguided research in mainstream psychology. Theory and Psychology, 8, 183-194.