اندازه گیری خوش بینی-بدبینی از اعتقادات در مورد رویدادهای آینده

Abstract In this study optimism–pessimism was defined in terms of an expectancy-value model based on subjective probabilities and subjective values for positive or negative future events in one's personal life and for positive or negative future general world events [Wenglert, L., & Svenson, O. (1982). Self-image and predictions about future events. Scandinavian Journal of Psychology, 23, 153–155]. The participants were 183 students. For each subject the correlation of probability and value ratings were computed separately for the sets of events. In a first analysis the sign of a coefficient categorised a subject as optimistic or pessimistic. 177 of 183 subjects were classified as optimistic about the personal future and six subjects as pessimistic. Considering the world's future, 155 persons were optimistic and 28 pessimistic. A second analysis used the value of a significant correlation (p<0.05) for 20 observations to obtain three groups: optimistic (r≥0.444), pessimistic (r≥− 0.444) and an intermediate group. By this rule 132, or 72%, were classified as optimistic about the personal future, 47 as neither optimistic nor pessimistic and no one as pessimistic. As to the world's future, 74 were optimistic and three were pessimistic. Into the intermediate group fell 106 Ss, or 58%. Optimism–pessimism about one's personal future was weakly associated with that for the general world.

. Introduction From many studies it has been reported that most people are optimistic as they believe that they are more likely than their fellow men to experience positive events and less likely to experience negative events. This has been found, for instance, when subjects were asked to predict the risk of getting involved in an automobile accident (Robertson, 1977) or the risk of being personally afflicted by various diseases or health problems (Kirscht, Haefner, Kegeles & Rosenstock, 1966; McGee & Cairns, 1994; McKenna, Warburton & Winwood, 1993; Peterson & De Avila, 1995). Similar results were also obtained when psychology students were asked to predict the probability of obtaining different grades at an examination (Teigen, 1983). Svenson (1981) showed that car drivers believe that they are less risky and more skilful than the average driver. Weinstein (1980) found students to be optimistic when estimating the probabilities for positive and negative future life events: for nearly every one of 18 positive events subjects rated their own chance as greater than the chance of the average same-sex student to achieve desirable outcomes and for nearly every one of 24 negative events they believed that the risk of personally experiencing them in the future was smaller than the average. Weinstein considered this kind of optimism to be a cognitive bias in judgement. He referred to it as unrealistic optimism about future vulnerability. At least some risk factors were perceived by the Ss to be controllable by psychological attributes or their own action ( Weinstein, 1980 and Weinstein, 1984). In Weinstein's study all events were of a personal character (e.g. ‘living past 80’ or ‘attempting suicide’). Fischer and Leitenberg (1986) studied 583 children in the age of 9 to 13 yr and their results were in line with those of Weinstein's involving young adults. Fischer and Leitenberg showed that the “overwhelming majority of the Ss were quite optimistic and minimally pessimistic” (op.cit.) in their expectancies of success and failure in personal life. Thus, not only adults but also children seem to be very optimistic in judging their personal future. Further, Cohn, Macfarlane, Yanez and Imai (1995) studied adolescents' and parents' perception of risks from various kinds of involvement in health-threatening activities and from frequent causes of morbidity and mortality. They found adolescents to be more optimistic than their parents about health-threatening behaviours but less optimistic about their chances of avoiding the most common causes of illness or death. The latter finding may suggest either an influence of the different timeframes of parents and adolescents when judging future events or more risk denial in parents. Optimism has been reported to have effects dependent on the time perspective used in predicting future events (Lipkus, Martz, Panter & Drigotas, 1993). Thus, several studies have shown that people are optimistic and believe more positive than negative things will happen to them in the future. Otherwise expressed, they have a general expectancy of positively valued outcomes of future life events. Three questions will be raised in the present study: (1) Are people optimistic about the future, when the concept of optimism is based not only on how likely they find various events to be but also on what value they place on each event? (2) Are people equally optimistic about events in their personal future life and about future world events with consequences of a more general nature? (3) If a person is optimistic about events in his or her future life, will this be related also to being more optimistic about world events generally? The approach to study optimism–pessimism in the present study explicitly considers both the subjective value of an event for the individual and its likelihood. Many studies have used ratings of perceived risks or subjective probabilities to infer the attitude to future events (Cohn et al., 1995, Lipkus et al., 1993, Weinstein, 1980 and Weinstein, 1984) without weighting the likelihood ratings by subjective estimates of value of the future outcomes. Starting from a decision-making model in situations involving risk Wenglert and Svenson (1982) studied the relation between attitude to self and the expected value of two sets of future events: in a person's life and in the world in general. For each individual they computed the correlation coefficients between subjective probability and subjective utility ratings for a set of events. They found a significant relation between self-attitude and the correlation of probability-utility ratings for personal but not for world events. The findings can be interpreted to support the hypothesis that the expectancies of personally relevant events are evaluatively consistent with the overall attitude to an object associated with the events. In the study of Wenglert and Svenson the attitudinal object was the self. They reported that all participants obtained a positive sign of the probability-utility correlation for personal events and could be described as `optimistic' in the sense that they believed that positively valued events in their personal future were likely and that negatively valued ones were not. For world events, the coefficients were negative for one third of the sample indicating a more `pessimistic' outlook on the future state of the world. Wenglert and Svenson (1982) applied one of the expectancy-value models that have appeared in several guises in the psychological research literature. The descriptive validity of the model in predicting behaviour has been the concern of many studies in different fields of psychology (Eagly et al., 1993, Feather and Feather, 1982 and Fishbein et al., 1975). In Scheier and Carver's model of behavioural self-regulation the variation in expectancies and affective experiences give rise to individual differences in optimism (Scheier, Carver & Bridges, 1994). In the present study optimism was defined in terms of an expectancy-value formulation, or equation(1) Full-size image (<1 K) where SE stands for subjective expected value, b refers to a belief about the occurrence of a particular event, e to the evaluation of the event and n is the number of beliefs and evaluations. The subjective expected value is then derived as the summed product of beliefs and evaluations. It is assumed here that beliefs can be interpreted as expectancies, or subjective probabilities of events. Wenglert and Svenson (1982) used the correlation between an individual's subjective probability and utility ratings, that is, a linear transformation of the standardised measure of the relation of the components of the subjective expected value model in Eq. (1). Their study was based on a small sample of 21 Ss, but the significant relation between self-attitude and the expectancy-value correlation indicating an optimistic attitude to future events in personal life has been replicated in later studies ( Wenglert, 1999; Wenglert & Rosén, 1995). Based on a definition of optimism in terms of an expectancy-value model two measures were used in the present study, one for general and one for personal optimism. Optimism–pessimism about the future for the world in general, with no or little control over environmental events, may reflect a generalised cognitive-social attitude to the state of the world. Optimism–pessimism about one's personal future, on the other hand, has been assumed to reflect the degree with which one believes in own ability to control or to cope with harmful situations (McKenna, 1993 and Scheier and Carver, 1987) and relate to self-esteem. The purpose of the present study was to examine individual differences in optimism–pessimism in both aspects and to explore if personal optimism–pessimism influences general optimism about world events.

. Results 3.1. Descriptive findings for items The items used to measure optimism–pessimism about personal and world events are listed in Table 2 in abbreviated form. They are shown in descending order of the mean expected value of the item in the sample of subjects. The mean probability and value ratings for each item are also shown. The ratings of the likelihood of future events were made by the subjects on a 0–100 scale recoded in the table as probabilities of 0–1. The mean of the probability ratings of the personal events was 0.489 (S.D.=0.067) and for world events. 356 (S.D.=0.097). The value ratings had a mean of 1.14 (S.D.=1.07) for personal and −2.92 (S.D.=1.16) for world events. The probability and value ratings correlated 0.323 for personal and 0.286 for world events, both correlations highly significant (p<0.001). Table 2. Items and their order of presentation for personal and world optimism. Items are shown in descending order of the mean expectancy (probability x value ratings) of each item. Mean probability and value ratings for each item are also shown. N=183 Personal events Expectancy Probability Value Item M S.D. M M 01…have gifted and healthy children 6.41 2.75 0.714 8.75 13…you will have, on balance, a happy life 6.29 2.42 0.709 8.79 03…will live with the man or woman really loved 6.22 2.76 0.665 9.04 06…your children, when grown-up, will still love you 6.02 3.26 0.708 8.28 29…when old, will feel that you have chosen your own life and not let things just happen to you 5.50 3.15 0.675 7.46 30…you succeed in your studies 5.34 3.57 0.754 6.49 18…your colleagues or work-mates will like you 4.98 2.48 0.733 6.66 05…get the job you really want to have 3.27 4.34 0.589 4.10 34…you will one day travel round the world 3.97 3.16 0.615 5.81 22…be able to keep your best friends throughout life 3.23 4.24 0.560 3.43 10…you will one day get a book published 1.95 2.36 0.332 4.25 16…you will be described or cited as an important expert in some field 1.93 2.39 0.417 3.89 39…when old, most people have regarded you as an unpleasant person −1.16 1.89 0.196 −6.05 40…you will suffer a middle-age crisis −1.23 2.21 0.479 −2.99 17…that you will fail in your profession or job −1.29 1.55 0.210 −6.48 38…when old, you will consider yourself as having been an insignificant person −1.41 2.09 0.263 −6.55 19…that you will be a poor mum or dad −1.75 2.14 0.241 −7.69 08…you will have an infarct or stroke within 30 years −2.00 2.02 0.254 −8.36 07…you will develop cancer in 15 years from now −2.42 2.08 0.288 −8.60 09…will be very lonely when old −2.55 2.46 0.341 −7.53 World events 32…there will be a black revolt in South Africaa 4.78 3.90 0.740 5.94 33…a third World War will never develop 4.71 3.37 0.538 8.59 28…that people will have ample leisure-time in the next decade 2.95 2.59 0.502 5.68 36…that in 20 years time the school will have changed and maintains the pupils' motivation to seek knowledge 2.87 2.56 0.402 6.65 27…that unemployment will be low in the next decade 1.98 2.43 0.326 5.51 24…the human race still exists 3.000 years from now 1.91 3.80 0.392 3.43 37…that the school will become very individualized within 20 years from now 1.84 2.73 0.397 3.90 02…a nuclear power plant disaster in Sweden in the next decade −0.26 4.71 0.574 −4.54 14…Sweden will be a communist country within 50 years −0.69 1.80 0.156 −4.96 23…Northern Europe will enter a new ice age in 100 years from now −0.73 1.27 0.113 −7.24 15…Sweden will be a fascist country within 50 years −1.13 1.95 0.156 −8.56 26…that we will be hit by a severe crisis in economy within 10 years from now −2.00 2.45 0.377 −5.90 12…that the human race is extinct in 100 years −2.03 2.51 0.275 −8.42 04…a third world war within the next 15 years −2.23 2.35 0.256 −9.14 25…more than half of the mammalian species, with the exception of humans, are extinct within 100 years −2.52 2.47 0.317 −8.41 31…most underdeveloped countries will be as poor in 40 years as at present −3.64 2.95 0.53 −7.24 11…oceans and lakes with be destroyed by pollutants within the next 40 years −3.81 2.85 0.425 −9.12 35…the forests of Amazonas will be devastated in 20 years from now −4.49 2.71 0.500 −8.90 a Data were collected shortly before the political change in South Africa. Table options The mean expected value (probability x value) of the 20 items referring to events in the personal future was 2.06 (S.D.=1.14) and for possible future world events −0.27 (S.D.=1.01). The correlation of personal and future expected values was 0.224 (p=0.002). The homogeneity of the two sets (Cronbach's α coefficient) was 0.744 and 0.649, respectively. The α coefficients were moderate as expected since the items had been sampled to cover a broad range of possible future events. The personal and world event items with the most positive and the most negative value rating on a ±10 scale were “…that, on balance, you will have a happy life” (M=8.79), “…that there will never be a third world war, because everyone realises that it would be a disaster” (M=8.59), “…that there will be a third world war within the next 15 years“ (M=−9.14), and ”…that you will develop cancer within the next 15 years (M= −8.60). The item “…that the human being still exists 3000 years from now” had a mean value rating of 3.43. This seems low when compared, for instance, with the item “…that you some day will be mentioned in a book/review/newspaper as an important person in some field” (M=3.89). That is, the latter event was seen — in the present sample of students — as slightly more important than the former. A probable explanation of the modest evaluative rating of continued human existence may be that it is difficult to imagine periods of future time extending thousands of years, even if this cognitive capacity is important for the survival of the human species. 3.2. Optimism–pessimism about personal and world events For each subject two correlation coefficients of probability and value ratings were computed as individual scores of personal optimism and world optimism. In the sample of 183 subjects the mean for personal optimism was 0.596 (S.D.=0.276) and for world optimism 0.336 (S.D.=0.331). The positive mean of both correlations suggested that the subjects had optimistic expectations. The mean difference between the two variables was highly significant (t for paired samples=9.53, d.f.=182, p=0.000) and replicated the finding of Wenglert and Svenson (1982). Thus the level of optimism was generally higher for outcomes of events in one's personal life. Background factors of sex and age (Table 1) were next examined by ANOVA. In personal optimism there was no effect of sex (F=0.44, ns) nor of age group (F=1.42, d.f.=2, ns) and no interaction (F=1.12, ns). For world optimism, sex was a significant factor (F=4.17, p=0.043) but neither age group (F=0.09, d.f.=2) nor the interaction term were (F=0.23, ns). The women were lower in world optimism (M=0.302, S.D.=0.337) than the men (M=0.431, S.D.=0.298). Two statistical analyses were calculated of the individual correlation coefficients used as scores in personal and world optimism, respectively, in order to classify the subjects as optimistic versus pessimistic. In the first analysis optimism was defined as a positive deviation, however small, from a correlation of zero and pessimism as a deviation in the negative direction. By this operational definition of optimism–pessimism 177 of 183 subjects, or 97%, were categorised as optimistic and only six as pessimistic. This distribution of cases would be obtained by chance less often than once in a million, if the proportions of optimistic and pessimistic persons in the population both are assumed to be 0.5. In world optimism a few more individuals were classified as pessimistic, as the correlation was negative for 28 subjects, or 15.3%, (p<0.0000). By the definition of optimism–pessimism from the sign of the correlation 152 subjects, or 83%, were classified as optimistic both in personal optimism and world optimism. Twenty-four subjects were optimistic in personal optimism but pessimistic in world optimism. In the second statistical analysis of the individual correlation coefficients, optimism–pessimism was defined from the value of a significant correlation (p<0.05) for 20 observations. This gave three groups of subjects: optimistic (r≥0.444), pessimistic (r≥−0.444) and one intermediate group with correlations in the range from 0.443 to −0.443. From this definition of optimism–pessimism, there were 136 subjects, or 74%, who were optimistic about events in the personal future. No one was pessimistic. There were 47 subjects with coefficients in the intermediate range and considered to be neither optimistic nor pessimistic. Thus, the tendency to be optimistic regarding the outcomes of possible future events in one's personal life was obvious in the sample (χ2=95.4, d.f.=2, p<0.000). On the other hand, for world events 74 subjects were optimistic, three were pessimistic and 106 had correlations in the intermediate range. Thus, most subjects, or 58%, were neither optimistic nor pessimistic as to the outcomes of general world events (χ2=91.1, d.f.=2, p<0.000). About 33 % of the Ss were classified as optimistic in both personal and world optimism. 3.3. The relationship of world to personal optimism The final analysis concerned the question whether optimism as an expectation of positive outcomes of personally relevant events will influence optimism–pessimism about events of the world in the same direction. The distributions for personal and world optimism were first examined. The scores in personal optimism were negatively skewed, deviating significantly from normality (Kolmogorov–Smirnov statistic=0.120, d.f.=183, p<0.000), but normally distributed in world optimism. Regressing world optimism on personal optimism showed that the two variables were significantly linearly related (F=14.54, p=0.0002) although with a weak association (r=0.273, p<0.001).