M. G. Carelli et al.:European Sw edishJournal Zimbardo of Psychological Time © 2011 Perspective Hogrefe Assessment Inventory Publishing 2011
Original Article
Development and Construct Validation of the Swedish Zimbardo Time Perspective Inventory Maria Grazia Carelli1, Britt Wiberg1, and Marie Wiberg2 1
Department of Psychology, Umeå University, Umeå, Sweden 2 Department of Statistics, Umeå University, Umeå, Sweden
Abstract. In this study, we developed and evaluated a Swedish version of the Zimbardo Time Perspective Inventory (ZTPI; Zimbardo & Boyd, 1999). The original version of the ZTPI was extended by including a Future Negative scale, and the psychometric properties of both versions were examined in a sample of 419 adults aged between 18 and 80 years. Confirmatory factor analysis (CFA) provided support both for the original five-factor solution proposed by Zimbardo and Boyd (1999) in a Swedish sample and for a six-factor solution with the Future Negative scale as an independent factor. These findings extend the original ZTPI and suggest that negative feelings about the future constitute a central dimension of the temporal perspective. The Swedish Zimbardo Time Perspective Inventory (S-ZTPI) provides a reliable and valid instrument for measuring time perspective in the context of Swedish research and to be beneficial in its application in multiple areas of psychology and related disciplines. Keywords: time perspective, ZTPI, S-ZTPI, temporal orientation, temporal cognitive frames
Introduction Time offers an important basis for helping us to understand our experiences in the world, including shaping our thoughts, lives, and existence. We draw on past memories, experience the present, and look forward to future rewards. These differences in time perspective (TP) may influence many everyday judgments, decisions, and actions. For example, Lewin (1951) stressed the impact of TP on psychological conditions. He also maintained that differences and biases in temporal orientation are influenced by the individual’s social background and motivational processes. More recently, Zimbardo and collaborators (e.g., Zimbardo, 2008; Zimbardo & Boyd, 1999) have focused efforts toward recognizing the centrality of TP in many domains of psychology. In their view, TP is a semi-conscious process in which temporal categories play a central role in the relationship between personal and social experiences that help to give meaning and order to everyday life events. Temporal cognitive frames are used in encoding, storing, and recalling experienced events, as well as in forming expectations, goals, and imaginative views. To measure TP, Zimbardo and colleagues developed the Zimbardo Time Perspective Inventory (ZTPI). The ZTPI consists of five subscales, Past Negative (PN), which reflects a pessimistic attitude toward the past and possibly the experience of traumatic life events; Past Positive (PP), © 2011 Hogrefe Publishing
which is marked by a more sentimental and positive view of one’s past; Present Hedonistic (PH), which is associated with the desire for spontaneous pleasure with slight regard to risk or concern for future consequences; the Present Fatalistic (PF), which is defined as a lack of hope for the future and belief that uncontrollable forces determine one’s fate; and the Future (F) scale, which is characterized by reward dependence that occurs as a result of achieving specific long-term goals. Research suggests that particular temporal frames have implications for various aspects of well-being. Specifically, PN is often associated with depression, anxiety, and low self-esteem. In contrast, PP is related to high levels of selfesteem and happiness (Zimbardo & Boyd, 1999), and agreeableness and energy (Goldberg & Maslach, 1996). Present oriented (PH and PF) individuals tend to engage in risky driving (Zimbardo, Keough, & Boyd, 1997), and alcohol and drug misuse (Keough, Zimbardo, & Boyd, 1999; Strathman, Gleicher, Boninger, & Edwards, 1994).
Developing an Extended Version of the ZTPI: The Future Negative Scale The future subscale of the ZTPI has been associated with less psychopathology (Wallace, 1956, cited in Zimbardo & Boyd, 1999), and is positively correlated with participation European Journal of Psychological Assessment 2011 DOI: 10.1027/1015-5759/a000076
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M. G. Carelli et al.: Swedish Zimbardo Time Perspective Inventory
in a cancer-screening program (Boyd & Zimbardo 2005). It is, therefore, regarded as the more constructive TP in terms of engaging in positive health behaviors. According to Zimbardo and Boyd (1999), individuals with a more future-oriented outlook are more optimistic and anticipate positive outcomes. This can, in itself, perpetuate more positive functioning and can lead to higher levels of academic achievement (Boyd & Zimbardo, 2005), elevated levels of participation in research studies (Harber, Zimbardo, & Boyd, 2003), and more adaptive coping strategies for obtaining shelter when homeless (Epel, Bandura, & Zimbardo, 1999). However, an overemphasis on future goals may compromise spontaneity, resulting in poor ability to “switch off” and to enjoy the present (Boniwell & Zimbardo, 2003). It seems that seeking immediate gratification, while disregarding the consequences of actions, is a typical predisposition to a present temporal bias. Although the ZTPI has been used and validated extensively in past research, we believe that its future-oriented dimension should be extended and better specified. Specifically, the future-oriented dimension includes a mixture of negative and positive items, whereas the past-orientation dimension is based on separate scales. In the original article, Zimbardo and Boyd (1999) were aware of the necessity to include a future subfactor: “By contrast, the ZTPI has but one future TP. Perhaps further factor analyses of our scale with a variety of non college populations will again show a more complex set of future subfactors” (Zimbardo & Boyd, 1999, p. 1284). Also, Worell and Mello (2007) suggested the possibility of a six-factor structure. However, they operationalized the sixth factor in terms of planning or positive aspects of the future. In the present study, we have extended the original version of the ZTPI by including the Future Positive (FP) and Future Negative (FN) constructs, respectively. Following the line of reasoning outlined above, our main argument was that the assessment of TP should not be limited to positive future evaluations. Instead the ZTPI should also include a negative dimension that involves thinking about the future with worry, anticipating negative outcomes, in a similar way as the PN TP is described in the original scale. Zalesky’s (1996) and Nurmi’s (2005) research on the relationship between future and affective aspects supports our argument. Both authors point out that the future TP is often described in positive terms. This bias seems reasonable as we usually associate the concept of future with hope, success, and related attributes. However, there are other kind of associations, such as fear, anxiety, preoccupation, and uncertainty. These negative aspects of the future TP are often neglected. The individual personal future must be conceived as evoking emotional and cognitive attitudes that range from positive (e.g., hope, joy, success) to negative attributes (e.g., concerns, anxiety). The aim of the present study was to examine the construct validity of the TP concept and to evaluate the psychometric properties of the original and the extended adaptation of the ZTPI in a sample of Swedish adults, referred European Journal of Psychological Assessment 2011
to as the Swedish Zimbardo Time Perspective Inventory (S-ZTPI). Furthermore, S-ZTPI scores were related to individual differences in impulsivity, as measured by the Barratt Impulsiveness Scale (BIS-11; Patton, Stanford, & Barratt, 1995), and decision-making style, as measured by the General Decision-Making Style (GDMS) instrument (Scott & Bruce, 1995). Our primary hypotheses were that present orientation would be positively associated with the spontaneous and intuitive dimensions of the GDMS, and that the rational decision-making style would be associated with future-oriented TP. Following past work, we also hypothesized that participants with PH temporal orientation would consider themselves as impulsive. As a support for this hypothesis, Zimbardo and Boyd (1999) reported that high scores on the PH scale were associated with low impulse control, as measured by the Impulse Control scale of the Big-Five Questionnaire (Caprara, Barbaranelli, Borgogni, & Perugini, 1993). We also reasoned that the FN and FP scales of the SZTPI might show different associations with impulsivity, as measured by the BIS-11 impulsiveness scale. Specifically, we hypothesized that FP would be negatively correlated with BIS-11, suggesting that individuals with a positive future orientation are less spontaneous and risk-taking than future negative individuals. The decision-making style data were expected to show a similar pattern in that the FP (but not FN) dimension of the S-ZTPI would show positive correlations with a rational decision-making style.
Method Participants The S-ZTPI was administered to a sample of 419 individuals living in a midsize town in northern Sweden. All participants had Swedish as their native language, and none of them had serious health problems or severe sensory deficits. The whole sample comprised 153 (36.5%) males and 266 (63.5%) females, between 18 and 80 years of age (M = 33.58, Md = 30, SD = 13.58). Two participants were excluded from the age-related analysis as they were considered as outliers within their age group, and five participants did not state their age.
Instruments Time Perspective Assessment of TP was based on the extension of the Swedish version of the ZTPI (S-ZTPI). The original version of the questionnaire (Zimbardo & Boyd, 1999) consists of 56 items and five subscales; Past Negative (PN), includes questions such as “I think about the good things that I have missed out on in my life,” Past Positive (PP) “It gives me pleasure to © 2011 Hogrefe Publishing
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Table 1. English translation of the new items of the Scale Future Negative (FN) (n = 8) in Swedish Zimbardo Time Perspective Inventory (S-ZTPI). The mean (M), standard deviation (SD), median (Mdn), and discrimination index (rs) of the new items, with item order in S-ZTPI in parenthesis (N = 419) No.
Item
M
SD
Mdn
rs
I (11)
I often think that I do not have time for everything I have planned to do in one day.
2.67
1.08
3
.38**
II (12)
Usually, I do not know how I will be able to fulfill my goals in life.
2.52
1.02
2
.43**
III (27)
At night I often reflect on tomorrow’s challenges.
3.41
0.97
4
.38**
IV (28)
I often feel that I cannot fulfill my obligations to friends and authorities.
2.16
0.93
2
.41**
V (39)
If I have to take a quick decision I am often worried that it was wrong.
2.99
1.16
3
.41**
VI (40)
I feel pressure not to be finished with different projects on time.
3.32
1.09
3
.47**
VII (63)
To think about my future makes me sad.
1.89
0.98
2
.26**
VIII (64) The future contains too many boring decisions that I do not want to think about. 1.88 1.01 2 .30** Note. The new items are raw translations and have not been tested empirically in English. The results apply only to the Swedish items. **p < .01.
think about my past,” Present Hedonistic (PH) “Taking risks keeps my life from becoming boring,” Present Fatalistic (PF) “Fate determines much in my life,” and Future (F) “I believe that a person’s day should be planned ahead each morning.” The S-ZTPI includes 64 items (56 items from the ZTPI and 8 new items (see Appendix) with four subscales from the ZTPI (PN, PP, PH, and PF) and two new scales, Future Negative (FN) and Future Positive (FP). The FN consists of 8 new items (e.g., “The future contains too many boring decisions that I do not want to think about,” see also Table 1) along with Items 9 and 18 from the original F scale of the ZTPI. The FP consisted of the remaining 11 original F items. The complete S-ZTPI in Swedish is available from the corresponding author. Translation and backtranslation of the original inventory and the new scale were provided by professional interpreters. We followed a common procedure of backtranslation in which a text is translated from a source into a target language, and a second interpreter independently translates the text back into the source language. The accuracy of the translation was evaluated by comparing the original and backtranslated versions (Hambleton, 2001; Van deVijer & Tanzer, 2004). As in the original ZTPI, responses were given on a 5-point Likert scale (1 = very uncharacteristic, 5 = very characteristic).
Impulsivity Individual differences in self-reported impulsivity were measured with the BIS-11 (Patton et al., 1995), which is a 30-item self-report scale, designed to measure general impulsiveness. The BIS-11 comprises the subscales of nonplanning impulsivity, motor impulsivity, and attentional impulsivity, respectively.
Decision-Making Style To assess individual differences in decision-making style we used the GDMS instrument of Scott and Bruce (1995). The GDMS is a 30-item questionnaire with five decisionmaking styles: rational style (i.e., searching for information © 2011 Hogrefe Publishing
and logically evaluating alternatives), intuitive style (i.e., attention to details and a tendency to rely on intuitions and feelings), dependent style (i.e., searching for advice and guidance from others), avoidant style (i.e., decision-making procrastination), and spontaneous style (i.e., feeling of immediacy and a need to end the decision-making as soon as possible).
Procedure Participants received the questionnaires together with a cover letter explaining the aim of the study. The data collection took place between November 2008 and March 2009. The questionnaires were completed by 419 participants, of which only 14 participants had one or two missing values on the ZTPI. Although missing values were replaced through the EM algorithm in SPSS 18.0, no significant change in standard deviation appeared.
Statistical Analysis First, the psychometric properties of the new items were examined, especially the mean, median, standard deviation, and item discrimination. Cronbach’s α was used to assess internal consistency in the scales. Spearman’s rank order correlation was used for examining test-retest reliability, the relationship between the subscales and background variables, and item discrimination in the new items, respectively. The ZTPI scale is ordinal and, hence, both parametric and nonparametric statistics were reported. When only parametric methods were used, the item distributions were examined if the assumptions were met. As there is substantial evidence for the factor structure of the original ZTPI (Milfont, Andrade, Belo, & Pessoa, 2008; Worrell & Mello, 2007; Zimbardo & Boyd, 1999) confirmatory factor analyses (CFA) on the ZTPI and S-ZTPI data were performed. In these analyses, four models were examined: (1) one-factor solution; (2) three-factor solution, which comprised the past (i.e., combined the PN and PP items into one factor), present (combined PH and PF items into one European Journal of Psychological Assessment 2011
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M. G. Carelli et al.: Swedish Zimbardo Time Perspective Inventory
Table 2. Mean (M), standard deviation (SD), and Cronbach’s α of the ZTPI and S-ZTPI together with the correlations among the subscales of ZTPI, S-ZTPI and age (N = 419) and correlations between ZTPI, S-ZTPI, and GDMS (n = 40) subscales α
PN
PP
PN
2.60
.69
.84
1.00
–
PP
3.58
.60
.76
–.23**
–
PF
2.49
.51
.65
.43**
PH
3.16
.52
.81
F
3.36
.48
.71
FN
2.62
.58
.75
Scale
M
SD
FP
3.36
.49
Age
33.58
13.58
.16** –.04 .68**
.70
–.08
–
–.28**
PF
–.10* .16**
.36** –.28**
.16*
F
FN
FP
–
.16** –.13*
PH
.35**
– –.29** –.05
– .12**
–
–.30**
–.28**
.96**
–.10
–.27**
.01
–.28**
.02
.36*
.33*
.24
–.06
.22
.03
.12
.05
.17
.67**
.27
–.06
.14
.48**
.08
–.05
.05
–
GDMS Intuitive Dependent Rational
–.11 .46** –.03
.35*
.06 .45**
Spontaneous
.41**
.02
.35*
.22
–.07
.31
–.02
Avoidant Note. *p < .05, **p < .001.
.51**
–.11
.27
–.03
–.10
.67**
–.17
factor), and future (combined FP and FN items into one factor); (3) five-factor solution using both the ZTPI and S-ZTPI scales (when using the S-ZTPI scale the FP and FN items were combined into one factor); and (4) six-factor solution on the S-ZTPI data. We did not add any correlations between the factors. The choice of models was influenced by Worrell and Mello (2007) and our explicit hypotheses. Specifically, the first three models above examined the factor structure of the original ZTPI (see also Milfont et al., 2008; Worrell & Mello, 2007; Zimbardo & Boyd, 1999), whereas the fourth analysis examined the validity of the extended S-ZTPI. AMOS 18.0 was used with maximum likelihood (ML) estimation. Note that, although ML makes assumption about multivariate normality, ML estimation is fairly robust to moderately nonnormal conditions and to categorical data (Lei & Lomax, 2005; Schermelleh-Engel, Moosbrugger, & Müller, 2003). As both skewness and kurtosis were less than 1.1, the ML estimation was considered appropriate. The CFA was based on Pearson’s correlations in order to facilitate comparison with previous studies. Furthermore, although the goodness-of-fit measures are better when using the polychoric correlation matrix, these values are generally good enough when using estimations based on Pearson correlations (e.g., Holgado-Tello, Chacón-Moscoso, Barbero-García, & VilaAbad, 2010).
Model Fit Model fit evaluation was based on χ², the ratio of the model χ² and degrees of freedom (χ²/df), root mean square error of approximation (RMSEA), standardized root mean square residual (SRMR), and comparative fit index (CFI), respectively, with suggested guidelines for model fit by European Journal of Psychological Assessment 2011
Schweizer (2010). Chi square-difference tests were used to compare fit of competing models (Tabachnick & Fidell, 2007).
Results Item Analysis of S-ZTPI Psychometric properties of the new constructed items belonging to FN are shown in Table 1. Both skewness and kurtosis were less than or equal to 1.1 for all items, indicating that the item distributions were similar to the rest of the items in the instrument and that the item distributions were rather symmetrical. The mean and median of the items in the FN scale were in line with the other scales and the standard deviations were similar for all eight items. The item discrimination was reasonably high with the exception of Item 63 “To think about my future makes me sad,” which was low.
Psychometric Evaluation of the Original ZTPI and the Extended S-ZTPI The psychometric properties of the ZTPI and S-ZTPI are summarized in Table 2. As shown in the upper part of Table 2, these data indicate consistent and reasonable values of mean, standard deviations, and internal consistency, respectively, for each scale. These data are also in line with the results of Zimbardo and Boyd (1999). Note that the FN and FP scales showed virtually identical internal consistencies with the F scale. The correlations among the subscales were in the expected directions. Note that FN was highly © 2011 Hogrefe Publishing
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Table 3. Fit indices for alternative models of CFA for ZTPI (56 items) and S-ZTPI (64 items) χ²
df
χ²/df
CFI
SRMR
RMSEA
Model 1
5647
1484
3.81
.32
.11
.08
Model 2
4298
1481
2.90
.54
.10
.07
Model 3
3783
1479
2.56
.63
.09
.06
Model 1
7194
1952
3.69
.34
.11
0.08
Model 2
6280
1950
3.22
.45
.11
0.07
Model 3
5489
1946
2.82
.55
.10
0.07
.09
0.06
ZTPI
S-ZTPI
Model 4 4951 1944 2.55 .62 Note. Model 1 = 1 factor, Model 2 = 3 factors, Model 3 = 5 factors, and Model 4 = 6 factors.
correlated with PN and that the F scale of the original ZTPI was highly correlated with the FP scale of the S-ZTPI (r = .96), whereas its association with the FN scale was substantially lower. The age correlations are consistent with earlier work, but the S-ZTPI shows an interesting pattern of results in that the age effect was accentuated in the FN items. Testretest reliabilities of the subscales of the ZTPI and S-ZTPI were established with a subsample of 30 participants. The time span between the two sessions was 2 weeks. All reliabilities were significant with p < .05. The highest test-retest reliability was observed for the PN (.85), followed by PH (.74), PF (.71), PP (.69), FN (.69), F (.64), and FP (.60). These correlations were consistent with earlier work involving larger samples. It should be noted that both the past and the future negative scales showed greater retest correlations than the corresponding positive scales.
el fit, whereas the CFI values were quite low. The χ² difference tests yielded a better fit for Model 4 than Model 3 (Δχ² = 538, df = 1, p < .001). One might suspect that the reason for the lack in achieving a really good model fit is the result of the restriction to not allow correlation among the latent variables’ respective factors. However, we have examined possible competing models where, e.g., the PN and FN factors were allowed to correlate and the model fit was not substantially improved. Because of this we decided to follow the principle of parsimony, which in this case meant to prefer the less complex model among the models with almost identical fit.
Confirmatory Factor Analysis
The concurrent validity of the S-ZTPI was assessed by relating its subscales to BIS-11 and GDMS. The BIS-11 data indicated that only the PH scale was significantly related to self-reported impulsivity (r = .40, p < .05) in that individuals with high overall BIS scores also had high PH scores. Furthermore, in the subscores, only the nonplanning impulsivity component was associated with PH (r = .47, p < .05), suggesting that participants who reported that they often “acted on the spur of the moment” (Patton et al., 1995, p. 769) also considered themselves as hedonistic persons who live in the present. Although not significant, the F scale of the original ZTPI and the FP scale of the S-ZTPI showed similar negative correlations, whereas the FN scale showed the opposite positive correlation with BIS-11. The GDMS data, which are summarized in the lower part of Table 2, were consistent with the BIS-data in that both the FP and F scales (but not FN) were significantly correlated with a rational decision-making style. Furthermore, both PN and FN were significantly correlated with the dependent and avoidant decision-making styles. This means that individuals with negative TP tend to avoid decisions or let others make decisions. Finally, PP, PH, and PF, respectively, were associated with the intuitive decision style.
ZTPI CFA was used to evaluate if the previously reported factor structure of the ZTPI was valid for our data (see Table 2). We used both model fit measures and χ²-difference scores in these model comparisons. Consistent with Zimbardo and Boyd (1999), the five-factor solution gave the best model fit. This solution was also supported by the χ²-difference test comparing Model 3 with Model 2 (Δχ² = 515, df = 2, p < .001). Note that the RMSEA, SRMR, and χ²/df all indicated a good or acceptable model fit but the CFI measure was low. These analyses were consistent with Worrell and Mello (2007) in that a five-factor solution provided the best fit, but that the model was only acceptable.
S-ZTPI The outcome of the CFA, shown in the lower part of Table 3, suggested that a six-factor solution yielded the best model fit. As with the ZTPI data, SRMR, RMSEA, and χ²/df, respectively, indicated a good or an acceptable mod© 2011 Hogrefe Publishing
S-ZTPI in Relation to Impulsivity and Decision-Making Style
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Discussion The aim of this study was to develop a Swedish version of the ZTPI, and to examine the factor structure of both the original ZTPI and the extended S-ZTPI in a Swedish sample of adults. Psychometric evaluation of the complete data indicated overall levels and distributions that were in close agreement with previous research (Milfont et al., 2008; Zimbardo & Boyd, 1999). The S-ZTPI data showed reasonable internal consistency, and the mean and standard deviations were consistent with Zimbardo and Boyd’s (1999) student sample. Although correlations were in the expected directions, only six coefficients were at or above .30. The F scale of the original ZTPI was highly correlated with the FP scale of the S-ZTPI (r = .96), whereas its association with the FN scale was very low. This pattern supports our hypothesis that the F scale of the original ZTPI is biased to emotionally positive events. The FN and FP items also had selective age effects in that these effects were accentuated in the FN items. In other words, older participants were less negative and worried about the future than younger participants, but they showed similar responses for the FP items. Furthermore, the age effect was eliminated for the original F items of the ZTPI, suggesting that the inclusion of both negative and positive items in the S-ZTPI increased the age sensitivity of self-reported future orientation. CFA was used to examine the factor structure of the original ZTPI, and these analyses indicated that the fivefactor structure proposed by Zimbardo and Boyd (1999) had the best fit to the data, although that fit was quite poor. This pattern of results suggests that the domains are not well represented by the ZPTI items. Nonetheless, the emergence of a recognizable factor structure with two or more core items (i.e., coefficients of the .5 or higher range) on each factor, suggests that TP constructs are potentially measurable in this age group. Another central finding of this study was that a six-factor solution yielded the best model fit of the S-ZTPI data. This result is consistent with our hypothesis and suggests that both negative and positive feeling about the future constitutes central dimensions of TP. Concurrent validity of the S-ZTPI was assessed by relating its subscales to measures of impulsivity and decision-making style. The expected significant relationship between PH temporal orientation and impulsivity was supported, suggesting that people who are oriented toward present enjoyment, pleasure, and excitement also consider themselves as impulsive. The GDMS data showed a similar pattern in that individuals with a negative temporal frame tend to adopt a decision style that is avoidant and dependent. On the contrary, individuals who are most oriented in the present tend to adopt a more intuitive and spontaneous decision style, probably mediated by reliance on hunches and feelings. European Journal of Psychological Assessment 2011
In conclusion, our findings support the construct validity of the S-ZTPI, suggesting that a negative feeling about the future constitutes a central dimension of TP. This extension of the original ZTPI seems to provide a reliable and valid instrument for standardized measurement of TP. Hence, by providing the possibility to measure a more complex set of future subfactors, we have contributed a fuller comprehension of the temporal perspective as a basic aspect of human activity.
Acknowledgments This study was financed by the Swedish Research Council, Research Project 220037 100 VR.
References Boyd, J. N., & Zimbardo, P. G. (2005). Time perspective, health, and risk taking. In A. Strathman & J. Joireman (Eds.), Understanding behavior in the context of time (pp. 85–107). Mahwah, NJ: Erlbaum, Publishers Boniwell, I., & Zimbardo, P. G. (2003). Time to find the right balance. The Psychologist, 16, 129–131. Caprara, G. V., Barbaranelli, C, Borgogni, L., & Perugini, M. (1993). The “Big Five Questionnaire”: A new questionnaire to assess the five factor model. Personality and Individual Differences, 15, 281–288. Epel, E. S., Bandura, A., & Zimbardo, P. G. (1999). Escaping homelessness: The influence of self-efficacy and time perspective on coping with homelessness. Journal of Applied Social Psychology, 29, 575–596. Goldberg, J., & Maslach, C. (1996). Understanding time: Connections between the past and future. Paper presented at the annual convention of the Western Psychological Association, San Jose, CA. Hambleton, R. K. (2001).The next generation of the ITC test translation and adaptation guidelines. European Journal of Psychological Assessment, 17, 164–172. Harber, K. D., Zimbardo, P. G., & Boyd, J. N. (2003). Participant self-selection biases as a function of individual differences in time perspective. Basic and Applied Social Psychology, 25, 255–264. Holgado-Tello, F. P., Chacón-Moscoso, S., Barbero-García, I., & Vila-Abad, E. (2010). Polychoric versus Pearson correlations in exploratory and confirmatory factor analysis of ordinal variables. Quality and Quantity, 44, 153–166. Keough, K. A., Zimbardo, P. G., & Boyd, J. N. (1999). Who’s smoking, drinking, and using drugs? Time perspective as a predictor of substance use. Basic and Applied Social Psychology, 21, 149–164. Lei, M., & Lomax, R. G. (2005). The effect of varying degrees of nonnormality in structural equation modeling. Structural Equation Modeling, 12, 1–27. Lewin, K. (1951). Field theory in the social sciences: Selected theoretical papers. New York: Harper. Milfont, T. L., Andrade, P. R., Belo, R. P., & Pessoa, V. S. (2008). © 2011 Hogrefe Publishing
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Testing Zimbardo Time Perspective Inventory in a Brazilian sample. Interamerican Journal of Psychology, 42, 49–58. Nurmi, J.-E. (2005). Thinking about and acting upon the future.Development of future orientation across the lifespan. In A. Strathman & J. Joireman (Eds.), Understanding behavior in the context of time (pp. 31–58). Mahwah, NJ: Lawrence Associates Publishers. Patton, J. H., Stanford, M. S., & Barratt, E. S. (1995). Factor structure of the Barratt Impulsiveness Scale. Journal of Clinical Psychology, 51, 768–774. Schermelleh-Engel, K., Moosbrugger, H., & Müller, H. (2003). Evaluating the fit of structural equation models: Tests of significance and descriptive goodness-of-fit measures. Methods of Psychological Research Online, 8, 23–74. Schweizer, K. (2010). Some guidelines concerning the modeling of traits and abilities in test construction. European Journal of Psychological Assessment, 26, 1–2. Scott, S. G., & Bruce, R. A. (1995). Decision-making style: The development and assessment of a new measure. Educational and Psychological Measurement, 55, 818–831. Strathman, A., Gleicher, F., Boninger, D. S., & Edwards, C. S. (1994). The consideration of future consequences: Weighing immediate and distant outcomes of behaviour. Journal of Personality and Social Psychology, 66, 742–752. Tabachnick, B. G., & Fidell, L. S. (2007). Using multivariate statistics (5th ed.). Boston: Allyn and Bacon. Van de Vijver, F., & Tanzer, N. K.(2004). Bias and equivalence in cross-cultural assessment: An overview. Revue Européenne de Psychologie Appliqué, 54, 119–135.
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Worrell, F. C., & Mello, Z. R. (2007). The reliability and validity of Zimbardo time perspective inventory scores in academically talented adolescents. Educational and Psychological Measurement, 67, 487–504. Zalesky, Z. (1996). Future anxiety. Concept measurement and preliminary research. Personality and Individual Differences, 21, 165–174. Zimbardo, P. G. (2008). The time paradox: The new psychology of time that will change your life. New York: Free Press. Zimbardo, P. G., & Boyd, J. N. (1999). Putting time in perspective: A valid, reliable individual-differences metric. Journal of Personality and Social psychology, 77, 1271–1288. Zimbardo, P. G., Keough, K. A., & Boyd, J. N. (1997). Present time perspective as a predictor of risky driving. Personality and Individual Differences, 23, 1007–1023.
Published online: June 20, 2011
Corresponding Author: Maria Grazia Carelli Department of Psychology Umeå University SE-901 87 Umeå Sweden Tel. +46 90 786-6404 E-mail
[email protected]
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Appendix The mean (M), standard deviation (SD), median (Mdn), and discrimination index (r) of the S-ZTPI (N = 419) Item
M
SD
Mdn
Item
M
SD
Mdn
1
2.81
1.17
3
rs .23**
33
3.29
1.06
3
rs .36**
2
3.78
0.94
4
.27**
34
3.74
0.88
4
.09
3
2.38
1.06
2
.37**
35
2.85
0.94
3
.30**
4
2.62
1.13
2
.52**
36
3.61
0.88
4
.17**
5
3.33
0.91
3
.27**
37
2.83
0.96
3
.44**
6
2.56
1.04
3
.14**
38
2.29
1.17
2
.43**
7
3.32
0.93
3
.03
39
2.99
1.16
3
.41**
8
3.09
0.95
3
.20**
40
3.32
1.09
3
.47**
9
3.27
1.15
3
.13**
41
2.69
1.05
3
.38**
10
3.56
0.92
4
.14**
42
2.56
1.03
2
.43**
11
2.67
1.08
3
.38**
43
3.26
0.95
3
.39**
12
2.52
1.02
2
.43**
44
2.27
0.93
2
.31**
13
3.93
1.04
4
45
2.61
1.10
2
.11**
14
3.21
1.16
3
46
3.38
0.82
3
.05*
15
3.34
1.04
3
.06
47
3.67
1.11
4
.05
16
1.81
.86
2
.29**
48
2.63
1.02
3
.33**
17
3.26
1.07
3
.29**
49
3.32
1.35
4
.24**
18
2.17
1.09
2
.47**
50
3.17
0.96
3
.25**
19
3.48
0.96
4
.12*
51
3.33
1.04
4
–.13**
20
3.51
1.13
4
.20**
52
3.33
0.90
3
.33**
21
3.03
1.29
3
.46**
53
2.48
1.11
2
.37**
22
3.57
0.93
4
23
4.02
0.85
4
24
2.74
1.14
3
25
2.89
0.91
3
26
3.37
1.04
3
27
3.41
0.97
4
.38**
28
2.16
0.93
2
29
3.82
1.13
30
3.28
31
3.07
32 2.93 Note. *p < .05, **p < .01.
–.03 .33**
54
3.40
0.83
3
.19**
55
3.61
1.05
4
.26**
.41**
56
2.34
1.04
2
.47**
.15**
57
3.43
0.89
4
.20**
58
2.60
1.03
3
.23**
59
2.26
0.89
2
.23**
.41**
60
2.09
1.02
2
.40**
4
–.23**
61
3.72
0.93
4
.33**
0.97
3
.38**
62
2.85
0.96
3
1.24
3
.43**
63
1.89
0.98
2
.26**
1.01
3
.21**
64
1.88
1.01
2
.30**
European Journal of Psychological Assessment 2011
.26** –.04
–.02
–.03
© 2011 Hogrefe Publishing
