The functional view of Snyder and his colleagues (e.g., Clary et al., 1998; Clary & Snyder, 1999; Omoto & Snyder, 1995, 2002) is focused on individual motives for helping. Functional theories maintain that one volunteers in order to satisfy one or more needs or motives. Different individuals can participate in the same volunteer work for very different reasons. Indeed, volunteering can satisfy different motives for the same individual at different times. Clary et al. identified six motives for volunteering: values (to express values related to altruistic and humanitarian concerns for others); understanding (to acquire new learning experiences and/or exercise skills that might otherwise go unused); social (to strengthen social relationships); career (to gain career-related experience); protective (to reduce negative feelings about oneself or address personal problems); and enhancement (to grow and develop psycho-logically). People are thought to persist in volunteering to the extent that the experience satisfies the relevant motive(s) (Clary & Snyder, 1991).

Existing data on the effect of satisfaction on volunteering are equivocal. Omoto and Snyder (1995) found that satisfaction was related to longevity of service among AIDS volunteers, and Clary et al. (1998), sampling from a variety of organizations, reported a positive association between satisfaction and intentions to continue volunteering. Similarly, Penner and Finkelstein (1998) found that satisfaction correlated significantly with both length of service and time spent volunteering at an AIDS service organization. Davis, Hall, and Meyer (2003) obtained less definitive results when they followed volunteers from an array of organizations throughout the first year of the volunteer process. Motive fulfillment did predict satisfaction, but satisfaction did not predict whether or not one persisted in volunteering and was only modestly related to time spent volunteering.

Penner (2002) suggested that a combination of the functional and role identity approaches might explain the processes that underlie long-term volunteering. He offered a conceptual framework that attributes the initial decision to volunteer to motive, prosocial personality, perceived expectations, and factors associated with various demographic characteristics (e.g., age, income, education). A high and involving level of activity produces a strong volunteer identity, which is thought to be the direct and proximal cause of sustained volunteerism. The hypotheses below stem from this conceptual view.

Aspects of Penner’s (2002) integrated framework have been helpful in explaining another long-term helping behavior, organizational citizenship behavior (OCB). OCBs are workplace activities that exceed the formal job requirements and contribute to the effective functioning of the organization. Like volunteerism, OCB represents a nonobligated, beneficial activity. Rioux and Penner (2001) found positive associations between self-reported OCB and two motives, namely prosocial values (the desire to help other individuals) and organizational concern (the desire to help the organization). In a sample of county employees, Finkelstein and Penner (2004) similarly found the amount of self- reported OCB correlated with the prosocial values and organizational concern motives. OCB also was related to the extent to which an employee developed an organizational citizen role identity.

In the current study, like that of Finkelstein and Penner (2004), we empirically examined the relationships among variables adapted from the functional and identity approaches. However, here the prosocial behavior of interest was volunteerism. We asked whether or not a combination of the two perspectives is useful in helping us to understand the factors that help sustain volunteering. Clearly, factors other than those examined here – such as the relationship between the individual and the organization – also influence volunteer activity (e.g., Penner & Finkelstein, 1998). Thus, the study is not meant to be exhaustive but to provide a preliminary empirical examination of Penner’s (2002) integrated conceptual framework.

For the first hypothesis, we drew from the work on motives, particularly Omoto and Snyder’s (1995) finding that motive strength was positively related to length of service in AIDS volunteers. Davis et al. (2003), in a longitudinal study of first-year volunteers, similarly found that motives predicted persistence as a volunteer. However, there was no relationship between either altruistic or self- oriented motivations and amount of time spent volunteering. We predicted a positive relationship between motives and both outcome variables (time and longevity).
Hypothesis 1: Motives will be positively associated with the amount of time spent volunteering at a hospice and with length of service.

The second set of hypotheses was derived from role identity theory and pertained to the relationship between others’ expectations and role identity, respectively and our two outcome measures. The strength of the volunteer self- concept has been shown to correlate with amount of current volunteer activity and intention to volunteer in the future. These relationships have been reported for a variety of types of volunteer service (Callero et al., 1987; Grube & Piliavin, 2000; Lee et al., 1999; see Piliavin et al., 2002 for additional references). These same studies showed a similarly positive relationship between perceived expectations and volunteer activity.
Hypothesis 2a: Role identity will correlate positively with amount of time devoted to hospice work and with length of service as a volunteer.
Hypothesis 2b: Perceived expectations about one’s hospice volunteering will be positively related to amount and length of service.

The third group of hypotheses involved the prosocial personality orientation. Here prior findings are contradictory. Penner and Finkelstein’s (1998) investigation of AIDS volunteers indicated that both other-oriented empathy and helpfulness were positively associated with length of service. Penner (2002) also found that the two factors of the PSB predicted both amount of activity and length of service in a variety of organizations. However, Omoto and Snyder (1995) found that concern for others was unrelated to length of service in AIDS volunteers. Instead, the data showed that volunteers were motivated primarily by personal, self-oriented functions. Similarly, Davis et al. (2003) reported no significant relationship between dispositional empathy (one of the components of the PSB) and either amount of participation or persistence with volunteering during the first year of service.

Because in the present study we used the same measure of prosocial personality as Penner and Finkelstein (1998) and Penner (2002), we predicted findings consistent with theirs. We also expected participants who scored higher on the other-oriented empathy factor of the PSB to develop a stronger volunteer self- concept.
Hypothesis 3a: Both factors of the PSB will show a positive relationship with length of volunteer service and amount of time spent volunteering at a hospice.
Hypothesis 3b: The other-oriented empathy factor of the PSB will correlate positively with a volunteer role identity.

Hypothesis 4 predicted a positive relationship between the altruistic values motive and a volunteer role identity. In their study of OCB, Finkelstein and Penner (2004) found that the strength of other-oriented motives (i.e., concerns for coworkers or for the organization) best predicted the strength of an organizational citizen identity. Citizenship behavior resulting from a desire for personal gain was uncorrelated with role identity.
Hypothesis 4: Role identity will correlate positively with the values motive.

We developed no specific hypotheses about the role of satisfaction in the volunteer process. As noted above, studies differ with respect to the role of satisfaction in maintaining volunteering.

The survey began with questions about the participants’ current level of involvement and length of service as a volunteer. Respondents indicated how much time they spend volunteering, choosing one of five response alternatives: less than one day per month, between 1 and 3 days per month, about 1 day per week, several days a week, and every day. For length of service, the choices were less than 3 months, between 3 and 6 months, between 7 and 11 months, between 1 and 2 years, and longer than 2 years. After answering questions about their age, gender, employment status, and level of education, participants completed measures of the following variables.

Volunteer motives Participants’ motives for volunteering were assessed with the Volunteer Function Inventory (VFI) developed by Clary et al. (1998). As discussed above, the inventory contains six scales, each comprising five items. Examples for each subscale include: “I am concerned about those less fortunate than myself” (values); “I can learn more about the cause for which I am working” (understanding); “My friends volunteer” (social); “Volunteering can help me get my foot in the door at a place where I’d like to work” (career); “No matter how bad I’ve been feeling, volunteering helps me to forget about it” (protective); and “Volunteering makes me feel important” (enhancement). A 5-point Likert response format was used, with alternatives ranging from 1 (not at all accurate/important for you) to 5 (extremely important/accurate for you). In the present study, the coefficient alphas for each scale were .69 (values), .83 (understanding), .81 (social), .92 (career), .78 (protective), and .84 (enhancement).

Volunteer role identity Specific identity as a hospice volunteer was measured with a modification of the five-item measure of role identity in blood donors used by Callero et al. (1987). Sample items include “Volunteering for Hospice is an important part of who I am” and “I really don’t have any clear feelings about volunteering for Hospice” (reverse scored). The 5-point rating scale had alternatives ranging from 1 (strongly disagree) to 5 (strongly agree). Coefficient alpha for this scale was .75.

Prosocial personality Prosocial tendencies were measured with the PSB (Penner, 2002; Penner et al., 1995). The 30-item self-report measure comprises two dimensions. One – other-oriented empathy – is the tendency to experience empathy and to feel responsibility for, and concern about, the well-being of others. In short, this factor refers to prosocial thoughts and feelings. The second factor, helpfulness, refers to a self-reported history of engaging in helpful, or prosocial, behaviors. Thus, the first factor primarily assesses cognitions and affect, while the latter assesses behavior. Cronbach’s alphas for the two scales were .83 (other-oriented empathy) and .76 (helpfulness). Again, response options ranged from 1 (strongly disagree) to 5 (strongly agree).

Volunteer satisfaction Satisfaction with participants’ volunteer work at the hospice was assessed with three items adapted from Penner and Finkelstein (1998): “I am satisfied with my experiences as a Hospice volunteer,” “I love my volunteer work,” and “Compared to other volunteers I know, I enjoy my volunteer work much more”. Responses again were measured in a Likert format from 1 to 5 (strongly disagree to strongly agree). The coefficient alpha in the present sample was .65.

Perceived expectations These refer to respondents’ perceptions of how salient their volunteering is to others and the extent to which important others expect them to continue that work. Perceived expectations were assessed with eight items adapted from the study of blood donors carried out by Callero et al. (1987). Examples include “Many of the people that I know expect me to continue as a Hospice volunteer” and “Many of the people that I know are not aware that I am a Hospice volunteer” (reverse scored). Respondents rated each item on a scale of 1 to 5 (strongly disagree to strongly agree). Coefficient alpha was .82.

The primary objective in the study was to examine associations among variables that are part of the functional and role identity models and to assess the relationships between these variables and volunteer activity. The results and discussion are organized around these measures and the hypotheses that were tested. Table 1 contains the correlations among the variables along with their means and standard deviations.

Hypothesis 1 predicted a positive relationship between the strength of all the motives and the two outcome measures: time spent volunteering and length of service. However, amount of time devoted to hospice correlated significantly only with the career motive and, contrary to expectation, the relationship was negative (r = -.26). Length of time as a hospice volunteer was significantly related to two motives, again both negatively: career (r = -.20) and understanding (r = -.12). Because these two motives were positively correlated with each other (r = .36), partial correlations were calculated to determine whether longevity was significantly associated with either motive after controlling for the other. The correlation between length and career motive decreased slightly but remained significant (r = -.17, p < .01), while that between length and understanding became nonsignificant (r = -.05).

The second set of hypotheses predicted a positive association between identity as a hospice volunteer and perceived expectations, respectively, and volunteer activity (Hypothesis 2a and 2b). Both hypotheses were supported. Time spent volunteering correlated r = .38 with role identity and r = .33 with perceived expectations, while longevity correlated r = .17 with identity and r = .26 with expectations.

We also anticipated (Hypothesis 3a) that a prosocial personality orientation would be directly correlated with time and length. However, neither the other- oriented empathy (altruistic affect and cognition) nor the helpfulness (prosocial behavior) dimensions of the PSB showed a significant correlation with either measure of volunteer participation. The data did support Hypothesis 3b, which predicted an association between the other-oriented empathy factor of the PSB and a volunteer role identity (r = .19). The relationship between helpfulness and role identity was not significant (r = .07); the difference between the two correlations approached significance [t(299) = 1.96, p = .05]. Turning to Hypothesis 4, as predicted, the values motive did correlate positively with role identity (r = .31), but so did several other motives. In fact, only the social motive failed to correlate significantly with a volunteer identity. The relationship was positive for understanding (r = .29), protective (r = .20), and enhancement (r = .25), and there were no significant differences among the four positive correlations. However, the Career motive correlated negatively with role identity (r = -.17).

The correlations contained in Table 1 suggest role identity and perceived expectations as important correlates of both length of volunteer service and amount of activity. However, the correlation matrix also revealed large intercorrelations among many of the variables examined. To examine whether the strong relationship between each of these two predictors and volunteer participation would remain with other variables partialled out, regression equations were calculated. The six motives, along with role identity, the two dimensions of prosocial personality, satisfaction, and perceived expectations were simultaneously entered as predictors of length of service and time given to hospice work, respectively. The results are shown in Table 2.

With regard to longevity, four of the variables had significant regression weights: perceived expectations (β = .23), other-oriented empathy (β = -.15), helpfulness (β = .13), and the motivation to acquire new learning experiences or exercise unused skills (understanding, β = -.19). The regression weights for expectations and understanding were consistent with their zero-order correlations (see Table 1). This was not the case for the two factors of the prosocial personality measure. Helpfulness, which had a nonsignificant zero- order correlation, had a significant regression weight, and the direction of the relationship between other-oriented empathy and longevity went from positive to negative. The changes strongly suggest a mutual suppression effect between the two personality variables which were themselves highly intercorrelated (r =.42). Cohen, Cohen, West, and Aiken (2003) described exactly this type of suppression effect (i.e., an increase in the strength of association and a change of sign): “[it indicates] that the relationship between independent or causal variables is hiding or suppressing the real relationship (with the criterion variable), which would be larger or possibly of the opposite sign were they not correlated” (p. 78). Thus, it appears that the two dimensions of the prosocial personality are related to longevity but certainly not in a simple or straightforward manner.

Significant predictors of the amount of time participants invested in volunteer work again included perceived expectations (β = .20) as well as role identity (β = .23). Two motives made significant contributions to the regression equations, both of them negative: social (β = -.13) and career (β = -.20).

The present results provide further support for role identity theory by replicating and extending earlier work. Perceived expectations and role identity were significantly related to volunteer activity (both time spent and length of service), with expectations a stronger correlate of volunteering than any other predictor variable. Piliavin and associates first used the concept of role identity to explain why some individuals continued to donate blood over an extended period. They subsequently adapted the theory to more traditional volunteer behaviors.

Thus, it would appear that the relationship between volunteering and the constructs contained in role identity theory is not behavior- or context-specific. Indeed, the relationship even extends to distinct but conceptually related behaviors such as OCB (see Finkelstein & Penner, 2004; Krueger, 2004). The individuals who are most likely to engage in ongoing, discretionary helping are those who have internalized a prosocial role and who strongly feel that others expect them to continue in a manner consistent with that role. Perhaps what is most impressive about the relationships found in this study and others is that role identity theory enables us to differentiate the level of involvement among active volunteers. That is, rather than predicting who will volunteer and who will not, it allows us to make predictions about who will be the most active or dedicated. The restriction of range in the behavior of interest (as all participants are already volunteering) makes for a much more difficult predictive task. Yet measures derived from the theory consistently enable us to do this.

Nonetheless, certain important questions remain about role identity, perceived expectations, and volunteering. The major ones concern causality. That is, does a volunteer role identity lead to longer and more active volunteering, or is the converse true? Both possibilities are plausible. The cross-sectional design of this work and of others we have cited prevents us from giving preference to one causal path over another. That is, the significant associations found in this study might reflect the causal impact of volunteer activity upon role identity, rather than the impact of role identity on volunteer activity. We are currently engaged in a longitudinal study of new hospice volunteers and this work should enable us to begin addressing such questions of cause and effect.

Turning to motives, the weak association with volunteer activity is not consistent with earlier studies showing a positive relationship between motives and both volunteering (e.g., Clary et al., 1998; Omoto & Snyder, 1995; Penner & Finkelstein, 1998) and OCB (e.g., Connell & Penner, 2004; Finkelstein & Penner, 2004; Rioux & Penner, 2001). The present data showed only a few significant relationships between motives and volunteer activity, and those relationships were not predicted. It may be worthwhile to consider a few post hoc explanations of the present findings.

One explanation may lie in the manner in which we assessed motives. Recall that although most of our participants were long-term hospice volunteers, they were asked about their initial motivations for volunteering. It is possible that their motives changed over time and that, had respondents reported current motivations, we would have found stronger associations with time and longevity. In the longitudinal study noted above, we are tracking motives across the course of the volunteer experience. Another possibility is suggested by the work of Davis et al. (2003). They proposed that it is not the importance placed on certain motives that maintains volunteering but the extent to which the motives are fulfilled by the experience. Clary et al. (1998) also examined volunteers in a variety of organizations and reported that with motive fulfillment came stronger intention to continue volunteering in both the short and long term. Had we examined the degree to which motives were met, perhaps a relationship between motive fulfillment and volunteering would have emerged. In this context, it is interesting that general satisfaction with one’s volunteer work did correlate significantly with level of volunteer activities.

It should also be noted that, although motives generally were uncorrelated with self-reports of volunteer tenure and activity, several motives did correlate with role identity and perceived expectations, both of which – in turn – were associated with volunteering. Further, the patterns of these associations were coherent and theoretically meaningful. For example, the strongest correlate of role identity was the values motive, while the career motive was negatively associated with role identity. Perceived expectations were more strongly related to the social motive than to any other motive. Thus, although motives were not related to volunteering in some simple straightforward manner, it would be premature to discount them as important correlates of volunteering. Perhaps, as Penner (2002) has suggested, their relationship to volunteering is mediated by role identity. Recently some have suggested that one can test for mediation even when a direct path is not significant (Shrout & Bolger, 2002). However, because we had not predicted such mediational processes, we did not test for them.

In contrast to earlier studies (e.g., Penner, 2002, Penner & Finkelstein, 1998), the zero-order correlations in this sample disclosed no association between volunteering and either dimension of the prosocial personality. The results of the multiple regression suggest that the relationship between longevity and personality was somehow hidden or suppressed by the relationship between the two personality dimensions. However, these kinds of suppression effects have not been reported in other studies using PSB. Thus, we are reluctant to speculate about why the effects occurred or how personality attributes were related to volunteering in this context.

In comparing the results of this study to those from other studies of volunteers, it is important to remember that our participants were disproportionately older and thus were more likely to be retired than are most volunteer samples. The age and employment status of our sample may account for the relatively high mean for the values motive (22.16 out of a possible 25; see Table 1) and relatively low mean for the career motive (8.18). Omoto, Snyder, and Martino (2000) also found that older hospice volunteers (age 55 and above) were motivated chiefly by the desire to be of service; interpersonal relationships were more important to younger volunteers. In the present sample, career motive correlated negatively with age (r = -.54, p < .001). When we controlled for age, the correlations between the career motive and both time spent volunteering and length of service became nonsignificant (r = -.09 and r = -.08). Perhaps with retirement comes the loss of the identity that a job provides and the need for a new identity (for example, as a volunteer) to take its place.

In the present study we examined a fairly homogeneous sample of volunteers. Most were older, long-term volunteers, and all worked for the same organization. It is likely that each of these characteristics influenced responses to the measures that were assessed in this study. Also, we do not know the characteristics of those volunteers who chose not to participate and who comprise 71% of the hospice’s volunteer population.

While Penner (2002) describes the development of the committed volunteer, in the present work we examined a cross-section of current volunteers. With the addition of our longitudinal data, we will undoubtedly be able to draw more definitive conclusions about the influence of motive and identity on the volunteer process.

Additionally, our focus was on dispositional more than organizational variables. A complete understanding of the volunteer dynamic must also consider characteristics of the organization and the interaction of the individual with the organization. For example, the hospice offers myriad volunteer opportunities ranging from duties that require high client contact (e.g., nursing home visitation, giving respite time to caregivers) to those that involve virtually none (e.g. office support, Speaker’s Bureau). The individual must be matched with the task to which he or she is best suited and in which he or she feels most comfortable (Stukas & Dunlap, 2002).

Callero, P. L., Howard, J. A., & Piliavin J. A. (1987). Helping behavior as role behavior: Disclosing social structure and history in the analysis of prosocial action. Social Psychology Quarterly, 50, 247-256.

Charng, H.-W., Piliavin, J. A., & Callero, P. L. (1988). Role identity and reasoned action in the prediction of repeated behavior. Social Psychology Quarterly, 51, 303-317.

Clary, E. G., & Snyder, M. (1991). A functional analysis of altruism and prosocial behavior: The case of volunteerism. In M. Clark (Ed.) Review of Personality and Social Psychology (pp. 119-148). Newbury Park, CA: Sage.

Clary, E. G., Snyder, M., Ridge, R. D., Copeland, J., Stukas, A. A., Haugen, J., & Miene, P. (1998). Understanding and assessing the motivations of volunteers: A functional approach. Journal of Personality and Social Psychology, 74, 1516-1530.

Clary, E. G., & Snyder, M. (1999). The motivations to volunteer: Theoretical and practical considerations. Current Directions in Psychological Science, 8, 156-159.

Cohen, J., Cohen, P., West, S., & Aiken, L. (2003). Applied multiple regression/ correlation analysis for the behavioral sciences (3rd ed.). Mahwah, NJ: Erlbaum.

Connell, P., & Penner, L. A. (2004). The antecedents of OCB: Motives as mediators. Paper presented at the meeting of the Society for Industrial and Organizational Psychology, Chicago, IL.

Davis, M. H., Hall, J. A., & Meyer, M. (2003). The first year: Influences on the satisfaction, involvement, and persistence of new community volunteers. Personality and Social Psychology Bulletin, 29, 248-260.

Finkelstein, M. A., & Penner, L. A. (2004). Predicting Organizational Citizenship Behavior: Integrating the functional and role identity approaches. Social Behavior and Personality: An international journal, 32, 383-398.

Grube, J., & Piliavin, J. A. (2000). Role identity, organizational experiences, and volunteer experiences. Personality and Social Psychology Bulletin, 26, 1108-1120.

Independent Sector. (2001). Giving and volunteering in the United States 2001. Retrieved September 3, 2004, from www.independentsector.org.

Krueger, T. (2004). The influence of an organizational citizen role identity on organizational citizenship. Unpublished doctoral dissertation, University of South Florida.

Lee, L., Piliavin, J. A., & Call, V. R. A. (1999). Giving time, money, and blood: Similarities and differences. Social Psychology Quarterly, 62, 276-290.

Midili, A., & Penner, L. A. (1995). Dispositional and environmental influences on organizational citizenship behavior. Paper presented at the meeting of the American Psychological Association, New York.

Omoto, A., & Snyder, M. (1995). Sustained helping without obligation: Motivation, longevity of service, and perceived attitude change among AIDS volunteers. Journal of Personality and Social Psychology, 68, 671-687.

Omoto, A., & Snyder, M. (2002). Considerations of community: The context and process of volunteerism. American Behavioral Scientist, 45, 846-867.

Omoto, A. M., Snyder, M., & Martino, S. C. (2000). Volunteerism and the life course: Investigating age-related agendas for action. Basic and Applied Social Psychology, 22, 181-197.

Penner, L. A. (2002). Dispositional and organizational influences on sustained volunteerism: An interactionist perspective. Journal of Social Issues, 58, 447-467.

Penner, L. A., & Finkelstein, M. A. (1998). Dispositional and structural determinants of volunteerism. Journal of Personality and Social Psychology, 74, 525-537.

Penner, L. A., Fritzsche, B. A., Craiger, J. P., & Freifeld, T. R. (1995). Measuring the prosocial personality. In J. Butcher & C. D. Spielberger (Eds.), Advances in personality assessment (Vol. 10, pp. 147-164). Hillsdale, NJ: Erlbaum.

Piliavin, J. A., & Callero, P. L. (1991). Giving blood: The development of an altruistic identity. Baltimore, MD: Johns Hopkins Press.

Piliavin, J. A., Grube, J. A., & Callero, P. L. (2002). Role as resource for action in public service. Journal of Social Issues, 58, 469-485.

Rioux, S., & Penner, L. A. (2001). The causes of organizational citizenship behavior: A motivational analysis. Journal of Applied Psychology, 86, 1303-1314.

Shrout, P. E., & Bolger, N. (2002). Mediation in experimental and nonexperimental studies: New procedures and recommendations. Psychological Methods, 7, 422-445.

Stukas, A. A., & Dunlap, M. R. (2002). Community involvement: Theoretical approaches and educational initiatives. Journal of Social Issues, 58, 411-427.

Callero, P. L., Howard, J. A., & Piliavin J. A. (1987). Helping behavior as role behavior: Disclosing social structure and history in the analysis of prosocial action. Social Psychology Quarterly, 50, 247-256.

Charng, H.-W., Piliavin, J. A., & Callero, P. L. (1988). Role identity and reasoned action in the prediction of repeated behavior. Social Psychology Quarterly, 51, 303-317.

Clary, E. G., & Snyder, M. (1991). A functional analysis of altruism and prosocial behavior: The case of volunteerism. In M. Clark (Ed.) Review of Personality and Social Psychology (pp. 119-148). Newbury Park, CA: Sage.

Clary, E. G., Snyder, M., Ridge, R. D., Copeland, J., Stukas, A. A., Haugen, J., & Miene, P. (1998). Understanding and assessing the motivations of volunteers: A functional approach. Journal of Personality and Social Psychology, 74, 1516-1530.

Clary, E. G., & Snyder, M. (1999). The motivations to volunteer: Theoretical and practical considerations. Current Directions in Psychological Science, 8, 156-159.

Cohen, J., Cohen, P., West, S., & Aiken, L. (2003). Applied multiple regression/ correlation analysis for the behavioral sciences (3rd ed.). Mahwah, NJ: Erlbaum.

Connell, P., & Penner, L. A. (2004). The antecedents of OCB: Motives as mediators. Paper presented at the meeting of the Society for Industrial and Organizational Psychology, Chicago, IL.

Davis, M. H., Hall, J. A., & Meyer, M. (2003). The first year: Influences on the satisfaction, involvement, and persistence of new community volunteers. Personality and Social Psychology Bulletin, 29, 248-260.

Finkelstein, M. A., & Penner, L. A. (2004). Predicting Organizational Citizenship Behavior: Integrating the functional and role identity approaches. Social Behavior and Personality: An international journal, 32, 383-398.

Grube, J., & Piliavin, J. A. (2000). Role identity, organizational experiences, and volunteer experiences. Personality and Social Psychology Bulletin, 26, 1108-1120.

Independent Sector. (2001). Giving and volunteering in the United States 2001. Retrieved September 3, 2004, from www.independentsector.org.

Krueger, T. (2004). The influence of an organizational citizen role identity on organizational citizenship. Unpublished doctoral dissertation, University of South Florida.

Lee, L., Piliavin, J. A., & Call, V. R. A. (1999). Giving time, money, and blood: Similarities and differences. Social Psychology Quarterly, 62, 276-290.

Midili, A., & Penner, L. A. (1995). Dispositional and environmental influences on organizational citizenship behavior. Paper presented at the meeting of the American Psychological Association, New York.

Omoto, A., & Snyder, M. (1995). Sustained helping without obligation: Motivation, longevity of service, and perceived attitude change among AIDS volunteers. Journal of Personality and Social Psychology, 68, 671-687.

Omoto, A., & Snyder, M. (2002). Considerations of community: The context and process of volunteerism. American Behavioral Scientist, 45, 846-867.

Omoto, A. M., Snyder, M., & Martino, S. C. (2000). Volunteerism and the life course: Investigating age-related agendas for action. Basic and Applied Social Psychology, 22, 181-197.

Penner, L. A. (2002). Dispositional and organizational influences on sustained volunteerism: An interactionist perspective. Journal of Social Issues, 58, 447-467.

Penner, L. A., & Finkelstein, M. A. (1998). Dispositional and structural determinants of volunteerism. Journal of Personality and Social Psychology, 74, 525-537.

Penner, L. A., Fritzsche, B. A., Craiger, J. P., & Freifeld, T. R. (1995). Measuring the prosocial personality. In J. Butcher & C. D. Spielberger (Eds.), Advances in personality assessment (Vol. 10, pp. 147-164). Hillsdale, NJ: Erlbaum.

Piliavin, J. A., & Callero, P. L. (1991). Giving blood: The development of an altruistic identity. Baltimore, MD: Johns Hopkins Press.

Piliavin, J. A., Grube, J. A., & Callero, P. L. (2002). Role as resource for action in public service. Journal of Social Issues, 58, 469-485.

Rioux, S., & Penner, L. A. (2001). The causes of organizational citizenship behavior: A motivational analysis. Journal of Applied Psychology, 86, 1303-1314.

Shrout, P. E., & Bolger, N. (2002). Mediation in experimental and nonexperimental studies: New procedures and recommendations. Psychological Methods, 7, 422-445.

Stukas, A. A., & Dunlap, M. R. (2002). Community involvement: Theoretical approaches and educational initiatives. Journal of Social Issues, 58, 411-427.