Intention, Expectation, and Willingness
Frederick X. Gibbons

In an effort to reduce the "literal inconsistency" problem (the inconsistency between what people say and what they do) and therefore increase the observed relation between proximal antecedents and behavior, researchers have explored other types of proximal measures.

Implementation Intentions
One way to increase the predictive power of intentions is to make them more concrete; i.e., add items regarding the specific ways in which the behavior may be performed, or the goal attained. In other words, ask about when the behavior will be performed, as well as where and how it will take place, what Gollwitzer (1999) xClose
Gollwitzer, P. M. (1999). Implementation intentions: Strong effects of simple plans. American Psychologist, 54, 493-503. calls implementation intentions (see examples in Measures). Adding these specifics has been shown to increase the likelihood that intentions to engage in behaviors, such as maintaining a healthy diet (Verplanken & Faes, 1999 xClose
Verplanken, B., & Faes, S. (1999). Good intentions, bad habits, and effects of forming implementation intentions on healthy eating. European Journal of Social Psychology, 29, 591-604. ), or engaging in breast self-examination (Orbell & Sheeran, 2000 xClose
Orbell, S. & Sheeran, P. (2000). Motivational and volitional processes in action initiation: A field study of the role of implementation intentions. Journal of Applied Social Psychology, 30, 780-797. ) will predict those behaviors—in part because it increases the likelihood that the behaviors will actually be performed (for a general review of implementation intention research, see Gollwitzer & Sheeran xClose
Gollwitzer, P. M., & Sheeran, P. (in press). Implementation intentions and goal achievement: A meta-analysis of effects and processes. Advances in Experimental Social Psychology. , in press). Forming these types of intentions is likely to be most important for health behaviors that are complex, and clearly linked with situational cues or prompts.

Behavioral Expectations
Intentions are defined as plans or goals. People oftentimes fall short of achieving their goals, however, which raises the question of whether respondents take this into account when stating their intentions. Assuming they often do not, Warshaw and Davis (1985) xClose
Warshaw, P. R., & Davis, F. D. (1984). Self-understanding and the accuracy of behavioral expectations. Personality & Social Psychology Bulletin, 10, 111-118. created the construct of behavioral expectation (BE), which they define as an estimate, or subjective probability, that a behavior will actually be performed (see Measures). Whereas BI is a plan, BE is a prediction. Theoretically, when answering BE items, people will take into account additional influential factors—circumstances, past behavior, anticipated change in intentions or circumstances—that might not enter into expressions of goals. Thus, BE should work better for behaviors that are undesirable and/or difficult; and there is some evidence of this (e.g., speeding; cf. Parker et al., 1992 xClose
Parker, D., Manstead, A. S. R., Stradling, S. G., Reason, J. T. & Baxter, J. S. (1992). Intention to commit driving violations: An application of the theory of planned behavior. Journal of Applied Psychology, 77, 94-101. ). Meta-analyses, however, have produced mixed support. Some have shown a slight, but significant superiority of BE for difficult or socially undesirable behaviors (Courneya & McAuley, 1994 xClose
Courneya, K. S., & McAuley, W. (1994). Are there different determinants of the frequency, intensity, and duration of physical Activity? Behavioral Medicine, 230, 84-90. ; Sheppard et al., 1988 xClose
Sheppard, B. H., Hartwick, J., & Warshaw, P. R. (1988). The theory of reasoned action: A meta-analysis of past research with recommendations for modifications and future research. Journal of Consumer Research, 15, 325-343. ); others report no difference (Sheeran & Orbell, 1998 xClose
Sheeran, P., & Orbell, S. (1998). Do intentions predict condom use? Meta-analysis and examination of six moderator variables. British Journal of Social Psychology, 37, 231-250. ; Webb & Sheeran, 2006). xClose
Webb, T. L., & Sheeran, P. (2006) Does changing behavioral intentions engender behavior change? A meta-analysis of the experimental evidence. Psychological Bulletin, 132, 249-268. One reason for this is that people are not very good at estimating the impact of influential factors that are presumably considered when forming expectations: peer pressure and past behavior, for example; nor are they very good at estimating or anticipating changes in circumstances or in intentions. Thus, BE and BI often end up looking very similar (Conner & Sparks, 1996 xClose
Conner, M. & Sparks, P. (1996). The theory of planned behaviour and health behaviours. In M. Conner & P. Sparks (Eds.), Predicting health behavior: Research and practice with social cognition models. (pp 121-162). Buckingham, England: Open University Press. ).

Many researchers have chosen to use BI and BE interchangeably. A meta-analysis of 154 TPB studies (Armitage & Conner, 2001 xClose
Armitage, C. J., & Conner, M. (2001). Efficacy of the theory of planned behaviour: A meta-analytic review. British Journal of Social Psychology, 40, 471-499. ) found that only 20 used straight BI measures; 40 used BE measures, and 88 used a combination of the two. Moreover, Davis and Warshaw (1992) xClose
Davis, F. D., & Warshaw, P. R. (1992). What do intention scales measure? Journal of General Psychology, 119, 391-407. present some evidence to suggest that people often report their expectations when answering BI questions. Clearly, there is a conceptual difference between behavioral goals and behavioral estimations—any smoker who has tried and failed to quit would attest to this. Similarly, asking a repeat DWI offender if s/he expects to drink and drive vs. whether s/he has a plan (or a goal) to drink and drive will result in very different responses. Empirically, however, the relative predictive validity of BE vs. BI measures for different types of behavior has not been clearly established (Webb & Sheeran, 2006) xClose
Webb, T. L., & Sheeran, P. (2006) Does changing behavioral intentions engender behavior change? A meta-analysis of the experimental evidence. Psychological Bulletin, 132, 249-268.; more research is needed.

Behavioral Willingness
When asked, most adolescents say they have no intention of engaging in behaviors that put their health at risk; and yet, when given the opportunity, many of them do (Gibbons, Gerrard, Reimer, & Pomery, 2006) xClose
Gibbons, F.X., Gerrard, M., Reimer, R. A., & Pomery, E. A. (2005). Unintentional behavior: A subrational approach to health risk. In D. de Ridder & J. de Wit (Eds.), New perspectives on health behavior: The role of self-regulation. . This is one reason why intentions are less effective at predicting adolescent behavior (Albarracín et al., 2001 xClose
Albarracín, D., Johnson, B. T., Fishbein, M., & Muellerleile, P. A. (2001). Theories of reasoned action and planned behavior as models of condom use: A meta-analysis. Psychological Bulletin, 127, 142-161. ; Sheeran & Orbell, 1998 xClose
Sheeran, P., & Orbell, S. (1998). Do intentions predict condom use? Meta-analysis and examination of six moderator variables. British Journal of Social Psychology, 37, 231-250. ), or behavior that involves health risk (Webb & Sheeran, 2006) xClose
Webb, T. L., & Sheeran, P. (2006) Does changing behavioral intentions engender behavior change? A meta-analysis of the experimental evidence. Psychological Bulletin, 132, 249-268.. In an effort to improve this type of prediction, Gibbons and Gerrard (1997) xClose
Gibbons, F. X., & Gerrard, M. (1997). Health images and their effects on health behavior. In B. P. Buunk, & F. X. Gibbons (Eds.), Health, coping, and well-being: Perspectives from social comparison theory. (pp. 63-94). Mahwah, NJ, US: Lawrence Erlbaum Associates, Publishers. ; Gibbons, Gerrard, & Lane, 2003 xClose
Gibbons, F. X., Gerrard, M., & Lane, D. J. (2003). A social reaction model of adolescent health risk. In J. Suls, & K. A. Wallston (Eds.), Social psychological foundations of health and illness. Blackwell series in health psychology and Behavioral Medicine (pp. 107-136). Malden, MA, US: Blackwell Publishers. ; in press) developed the prototype / willingness (prototype) model of health behavior. The basic contention of the model is that much health risk behavior (binge drinking, risky sex), especially among adolescents, is not intentional, but rather a reaction to social circumstances.

To capture this unintentional, reactive component of risky behavior, Gibbons and Gerrard created the construct of behavioral willingness (BW), which they define as an openness to risk opportunity—what an individual would be willing to do under some circumstances. To assess BW ( see Measures), risk-conducive situations are described, along with the qualifier that no assumptions are being made about whether the respondent would ever be in (or seek out) these types of situations. The intent is to avoid implied internal attribution or "blame." After describing the situation, a series of possible responses is described, which increase in level of risk. The aggregated total provides an assessment of what kinds of risky behavior the respondent is capable of performing—if they encounter the opportunity.

BW is highly correlated with BI, but still consistently explains additional amounts of variance in behavior—from 2% to > 10% (see Gibbons et al., 2003, for reviews xClose
Gibbons, F. X., Gerrard, M., & Lane, D. J. (2003). A social reaction model of adolescent health risk. In J. Suls, & K. A. Wallston (Eds.), Social psychological foundations of health and illness. Blackwell series in health psychology and Behavioral Medicine (pp. 107-136). Malden, MA, US: Blackwell Publishers. ). Moreover, as might be expected, BW is usually a better predictor than BI of health risk behavior for adolescents (Gerrard Gibbons, Stock, Dykstra, & Houlihan, 2005 xClose
Gerrard, M., Gibbons, F.X., Stock, M.L., Dykstra, J.L, Houlihan, A.E. (2005). The power of positive images: The role of social comparison in self-regulation. In D. de Ridder & J. de Wit (Eds.), New perspectives on health behavior: The role of self-regulation. ; Gibbons, Gerrard, Ouellette, & Burzette, 1998 xClose
Gibbons, F. X., Gerrard, M., Ouellette, J. A., & Burzette, R. (1998). Cognitive antecedents to adolescent health risk: Discriminating between behavioral intention and behavioral willingness. Psychology and Health, 13, 319-339. ; Gibbons et al., 2004 xClose
Gibbons, F.X., Gerrard, M., Vande Lune, L.S., Wills, T.A., Brody, G., & Conger, R.D. (2004). Context and cognition: Environmental risk, social influence, and adolescent substance use. Personality and Social Psychology Bulletin, 30, 1048-1061. ); then, with age and experience, BE and BI eventually exceed BW (Pomery, Gibbons, Gerrard, & Reis-Bergan, 2005 xClose
Pomery, E. A., Gibbons, F. X., Gerrard, M., & Reis-Bergan, M. (2005). Experience as a moderator of the developmental shift from willingness to intentions. Manuscript in preparation. ). Nonetheless, there are certain risky behaviors that, for many people remain "opportunistic" throughout life—adultery, for example, or risky sex, drunk driving, or recreational drug use.