Stress and work performance: The role of trait anxiety

Person. bdiuid. DfJ Vol. 20, No. 6, pp. 685-691, 1996 Copyright 0 1996 Elsevier Science Ltd Printed in Great Britain. All rights reserved 0191-8869/% $15.00+0.00 SO191-88fS(%)OM25-6

STRESS AND WORK PERFORMANCE: THE ROLE OF TRAIT ANXIETY Shahien Mughal, James Walsh and John Wilding* Department

of Psychology, Royal Holloway, University of London, Egham Hill, Egham. Surrey TW20 OEX, England (Received 25 September 1995)

Summary-Employees high in Trait Anxiety (TA) were found to exert greater work effort than those low in TA, which resulted in better sales performance. There was no relation between TA and work efficiency, measured by sales performance relative to work effort. Employees high in TA also reported greater levels of stress and more adverse effects of work on non-work relationships. Using multiple regression, both stress and interference with relationships were found to be better predicted by TA than work effort. The results are discussed in terms of laboratory-based theories about relations between TA and efficiency and intervention strategies for managing stress at work. Copyright 0 1996 Elsevier Science Ltd

INTRODUCTION

Spence and Spence (1966) claimed that the association between anxiety and performance was mediated by the level of task difficulty in relation to individual ability, so that anxiety would enhance performance on simple tasks but impair it on more complex tasks. In a review of 54 relevant studies, Eysenck (1982) found supportive evidence for Spence and Spence’s prediction in only 14 cases. Eysenck’s alternative theory (1979, 1982) proposed a distinction between performance “effectiveness” and “efficiency”. The former constitutes a basic index of performance “quantity”, whilst the latter adjusts this according to the amount of effort, or processing resources, invested. Subjects high in anxiety allegedly invest greater task effort in attaining a given level of effectiveness, with a resulting reduction in efficiency. This theory has been tested using dual-processing tasks (Kahneman, 1973) with secondary task performance believed to index spare processing capacity and hence reflect the amount of effort invested in the primary task. In a review of 16 dual task studies where no primary task differences were observed, anxiety was associated with a detrimental effect on secondary processing in 11 cases (Eysenck, 1982). Anxious subjects, therefore, appeared to expend greater effort on the primary task, with no discernible performance advantage, leaving less capacity for the secondary task. Much of the theoretical framework underlying TA has evolved from laboratory research. Explicit hypotheses, however, have rarely accompanied its inclusion in occupational stress research (Pratt, 1978; Kahn & Cooper, 1990). Two studies reported here enabled the testing of three hypotheses in an applied setting (Insurance Sales Personnel). Both effectiveness and efficiency of work performance were measured, and the first hypothesis was: owing to enhanced effort, high anxious subjects would demonstrate performance that was (a) no less effective but (b) less efficient than that of subjects low in anxiety. Trait anxiety and self-reported stress

Efforts to identify the mechanisms involved in TA have met with some success (for reviews see MacLeod, 1990; Eysenck & Mogg, 1991). High anxious subjects display a variety of information processing biases. They are more likely to (a) attend to threat-related as opposed to neutral stimuli; (b) interpret threat from ambiguous stimuli; (c) preferentially recall (implicitly) threatrelated information. Subjective, as opposed to objective, measures of stress and somatic complaints tend to be con-

* To whom all correspondence should be addressed. 685

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Shahien Mughal et al.

sistently and positively associated with trait anxiety and related constructs (Costa & McCrae, 1987). The potentially causal influence of TA on the reporting of stress has been examined in a number of recent studies with mixed results. For example, when Negative Affectivity was partialled out of the relationship between job stress and job strain, the previously significant association disappeared (Brief, Burke, George, Robinson & Webster, 1988), suggesting that NA was responsible for scores on both measures. Failures to replicate this were, however, reported by Chen and Spector (1991) and Jex and Spector (in press). The possibility exists that other factors may underpin this jobstress/strain relationship, work effort being one such candidate. The second aim, therefore, was to assess the influence of work effort on the relationship between trait anxiety and self-reported stress. More specifically, if the predicted association between TA and stress disappears when effort is partialled out of the equation, the latter may be regarded legitimately as the important mediator (provided of course that a significant relationship is also apparent between effort and stress). Conversely, if such a relation between work effort and stress disappears when TA is partialled out and the relation between TA and stress is significant, this would indicate that only TA is important in predicting reported stress. Problems at the home/work interface have rarely been examined in the literature despite their explicit inclusion in Cooper and Marshall’s (1976) early model of occupational stress. Gowler and Legg (1975) suggest that stress may arise over the allocation of resources (in particular, of time and commitment) to family and work. Therefore, in the present study ratings of the adverse effect of work on relationships with partners were obtained, the third aim of the study being to test whether subjects exerting greater work effort would report more adverse effects. However, TA could have a direct impact on relationship quality unmediated by work effort. A more complete test of this aim, therefore, required comparison of the extent to which effort predicted effects on relationships with TA removed, and the extent to which TA predicted such effects with effort removed.

STUDY

l-METHOD

Subjects Seventy-five insurance sales consultants, each with at least six months experience, were approached through six London branches of a national company. Thirty-two males and 16 females responded. Mean age for the sample was 29.5 yr (s.d. = 3.64). Materials (1) Biographical measures-subjects were asked to provide details of sex, age, and length of service. An additional question on the perceived adverse influence of work on relationship with spouse or partner was included with a four-point rating scale ranging from zero (no influence) to three (adverse influence). (2) The State-Trait Anxiety Inventory (STAI) comprises separate self-report scales for measuring state anxiety (SA) and trait anxiety (TA) (Spielberger, Gorsuch & Lushene, 1970). TA was employed in the present study. Each item is scored on a 4-point rating scale, with higher scores indicating greater anxiety levels. (3) The Brief Symptom Inventory (BSI-Derogatis & Melisaratos, 1983) is a 53-item self-report measure of current psychological symptom status. It consists of nine primary scales, including depression, anxiety, paranoia, hostility and somatic symptoms, and was used here to index overall psychological stress responsivity. Extensive reliability and validatory support is provided by the authors. Subjects simply indicate those symptoms which they are currently experiencing and from these reports the separate symptom scores and a total score are obtained. Only the total symptom score was used here (for simplicity it will be referred to as a measure of stress but it should be emphasized that it reflects a range of adverse reactions). (4) Performance measures-subjects were asked for diary details about their work during the previous month (February). This is a fairly typical working month when business picks up again after a post-Christmas lull. These diary records were entered daily by the subjects and were the source of reports to supervisors and records of each employee’s performance. They were, therefore, the most objective data available without tracking each subject throughout the working period.

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687

Table 1. Correlations of Text Anxiety, reported Stress and reported problems in personal relations with measures of effectiveness and effort expended in Study I

1. 2. 3. 4. 5. 6. 7. 8.

Trait Anxiety Stress Effectiveness Sales closed Appointments People seen Hours/month Relationship effects

0.78

3

4

5

6

7

0.28 0.43

0.29 0.23 0.52

0.32 0.47 0.09 0.07

0.30 0.51 0.31 0.21 0.81

8

0.29 0.25 0.02 -0.16 0.22 0.24

0.58 0.46 0.33 0.39 0.17 0.16 -0.01

roO, = 0.28; 1.~0~ = 0.37; ro.m, = 0.46.

Performance effectiveness was indexed by two measures, commission volume (CV), which represents the amount of business written when commission rate and policy type are considered, and the number of sales closed. These subjects were not assigned to specific geographical areas, but were free to create their own leads and contacts, so CV was not subject to biasses from extraneous constraints imposed by managers. Work effort was assessed using three measures from the diary records, the number of appointments made, the number of people seen and the number of hours worked. Six efficiency measures were obtained by dividing the two measures of effectiveness (CV and sales closed) by the three measures of work effort. Design and Procedure

Booklets containing the TA, BSI, performance and biographical questionnaires, together with addressed envelopes, were distributed via senior managers at the brokerages. A covering letter explained that the purpose of the study was to examine the relationship between personality and wellbeing in the workplace. Subjects were not asked to identify themselves beyond age and sex details, and were assured that the data would be treated in strictest confidence and would not affect their employment in any way. A total of 48 usable questionnaire booklets were returned representing a response rate of 68%. RESULTS A significant sex difference was noted in the effectiveness variable with males generating higher levels of commission volume (t = 2.60, d.f. = 46, p = O.Ol), but there was no sex difference in sales closed (t = 1.30). No sex differences were noted for age, trait anxiety, stress, length of service or the measures of work effort. Table 1 presents correlations between Trait Anxiety, Stress, work effectiveness and work effort. Table 2 presents parallel correlations for the measures of work efficiency. Table 2. Correlations of Test Anxiety, reported Stress and reported problems in personal relations with measures of efficiency in Study 1 (effectiveness divided by effort) Measure

1. Trait Anxiety 2. stress 8. Relationship effects

2

8

9

0.78

0.58 0.46

-0.02 -0.16 -0.04

10 -0.08 -0.22 -0.05

II

12

13

14

-0.02 -0.04 0.24

0.02 -0.17 0.23

0.01 -0.19 0.24

0.04 -0.13 0.27

0.41 0.47

0.30 0.30 0.65

0.25 0.29 0.64

0.18 0.19 0.68

0.99

0.98 0.98

Efficiency (CV/Effort): 9. CV/Appointments 10. CV/People seen I 1. CV/Time

0.96

Efficiency (Sales/Effort): 12. Sales/Appointments 13. Sales/People seen 14. Sales/Time r,,, = 0.28; r,,o, = 0.37; ro.,, = 0.46

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Multiple regression analyses were used to test each of the three hypotheses, with sex differences statistically controlled for in each case. Contrary to Hypothesis l(a), marginally significant relations between TA and effectiveness levels were found (t = 1.88, p = 0.07 for CV and t = 1.94, p = 0.06 for sales closed), indicating that high anxious subjects tended to generate greater levels of CV and sales. Anxious subjects also appeared to exert greater effort in terms of the number of appointments made (1= 2.40,~ = 0.02) and the number of people seen (t = 2.21, p = 0.03) but no TA differences emerged regarding the number of hours worked per month. Contrary to Hypothesis l(b), none of the efficiency measures varied with TA (t values ranged from -0.73 to 0.21). The second hypothesis predicted that, because high anxious subjects would have to exert greater effort in order to maintain equivalent performance levels, this may induce greater stress levels. As expected a highly significant positive correlation was noted between TA and stress (r = 0.78, p < O.OOl), but the indices of effort were also significantly related to stress (see Table 1). Using multiple regression equations, TA and sex were entered first, with stress as the dependent variable, and yielded t values of 8.43 (p < 0.001) and -0.41 (p < 0.05) respectively. Inclusion of the three measures of effort had little effect on these values (t = 7.68 and -0.90). Reported stress was also significantly related to CV, and this relation survived the inclusion of TA in the equation (t = 2.77, p < 0.01). However, the significant relation of TA to stress was not affected by including CV (t = 8.03). Thus subjects higher in TA reported more stress. Effort at work had little relation to such reports, but effectiveness as measured by CV was positively related to reported stress. It is impossible to infer the direction of causation in the latter case without additional data. Similar procedures were used to examine relations between TA, work effort and perceived effect on relationship. When TA and sex were entered first as predictors, t values of 4.89 (p < 0.001) and -2.13 (p < 0.05) were obtained. Addition of the three measures of work effort had only minor effects on these values. Hence, subjects higher in TA and female subjects reported more adverse effect of work on relationships. None of the relations between the measures of effort and relationship effects or productivity and relationship effects approached significance (t values ranged from - 1.06 to 1.45). Finally, in each of the above cases the first order interactions of TA with the effort and performance variables were also entered into the regression equations. The interaction effects were negligible in all cases except one. TA and sales closed interacted significantly in predicting adverse effects on relationships (t = 2.36, p = 0.02). Subjects scoring low on both variables or high on both variables reported significantly fewer effects than those scoring high on one variable and low on the other. To summarise, the results of the first study demonstrated that subjects high in Trait anxiety exerted more effort and were more productive, but did not differ in efficiency from less anxious subjects, contrary to the first hypothesis. They also reported more stress and more adverse effects of work on personal relationships. Measures of effort and productivity demonstrated few consistent relations with either stress or effects on personal relationships. Discussion of these results will be postponed until results of the second study have been reported.

STUDY

2-DESIGN

The second study provided a near replication of the first on a group of subjects drawn from six offices of a different company, ranging from Romford to Southampton. The study was carried out in October, again a fairly typical month. A total of 51 useable sets of questionnaires were returned from an initial sample of 128. Respondents consisted of 45 males and 6 females, with a mean age of 34.5 yr (s.d. = 9.27) and mean length of service of 2.46 yr (s.d. = 2.10). Most measures were identical to those of the first study. However in an effort to obtain a purer measure of stress the Stress-Arousal scale (Cruickshank, 1984) was employed, which is a specific measure of currently self-rated stress and arousal, consisting of 26 questions, 8 measuring arousal and 18 measuring stress. Subjects rated themselves on a 4-point scale (+ + f - - -) and one point is awarded for each high stress question attracting a positive rating (+ + or +) and each low stress question attracting a negative rating (- - or -). Thus the stress measure in Study 2 was not directly comparable with the more general measure employed in Study 1. Performance measures were a direct measure of amount earned (CV figures being unavailable) and sales closed. Subjects in the

689

The role of trait anxiety Table 3. Correlations of Test Anxiety, reported Stress and reported problems in personal relations with measures of effectiveness and effort expended in Study 2 Measure

1. Trait Anxiety 2. stress 3. Effectiveness 4. Sales closed 5. Appointments 6. People seen 7. Relationship quality

2

3

4

5

6

7

0.36

0.30 0.17

0.40 0.23 0.64

0.35 0.05 0.43 0.60

0.39 0.17 0.53 0.72 0.68

-0.07 -0.13 0.09 -0.01 0.17 -0.04

roo3= 0.28; roO, = 0.36; r,,w, = 0.45.

second study were less experienced and performance on both measures was lower than in Study 1. A slightly different system of appointments had been introduced, following new regulations for financial services. Potential customers were seen twice, the first time briefly to assess interest and the second time for completion of recommendations agreed at the first appointment. The number of second visits was comparable with the appointments measure employed in Study 1. The number of people seen was measured as before, but hours worked was not used as it did not provide any useful extra information in the first study. Four efficiency measures were obtained by dividing the two performance measures by numbers of appointments and people seen. In the first study subjects were asked to rate adverse effects of work on relationship with partner. Since this was a loaded question, it was decided to ask instead for a straightforward rating of quality of relationship with partner, on a 7-point scale, ranging from 0 (poor) to 7 (good). RESULTS

No significant sex differences were found in any variable. Tables 3 and 4 give the correlations. Multiple regression analyses were carried out as before, with the following results. Subjects with higher TA scores produced more (t = 2.3, p = ~0.03) and closed more sales (t = 3.14, p < 0.003), made more appointments (t = 2.78, p c 0.08) and saw more people (t = 3.05, p < 0.004). TA was not significantly related to the efficiency measures (t values ranged from - 1.06 to 0.76). These results all confirm those of the first study. TA was positively related to the new index of stress but less strongly than it was related to the measure used in Study 1 (r = 0.36, p < 0.05). Indices of effort were not significantly related to stress (Table 3). Multiple regression showed that TA alone was related to stress and the relation was not modified by inclusion of effort measures (for TA, t = 2.62) or performance measures (t = 2.25). This confirmed the finding of Study 1, though the relation was weaker in Study 2, where a more specific measure of stress was employed. This change in the measure of stress may also explain the absence of any relation between effort and stress in Study 2. Table 4. Correlations of Test Anxiety, reported Stress and reported problems in personal relations with measures of efficiency in Study 2 (effectiveness divided by effort) Measure

1. Trait Anxiety 2. Stress 7. Relationship quality

2

7

8

0.36

-0.07 -0.14

0.01 0.07 0.03

9

10

11

-0.11 -0.01 0.14

0.11 0.18 -0.09

-0.15 -0.13 0.07

0.77

0.38 0.06

-0.13 0.14

Efficiency (CV/Effort): 8. CV/Appointments 9. CV/People seen Efficiency (Sales/Effort): 10. Sales/Appointments 11. Sales/People seen r,,.or= 0.28; roO, = 0.36; row, = 0.45

0.43

690

Shahien Mughal et al.

No relation was found between TA and quality of personal relationships, either when TA was considered alone or jointly with effort and performance variables. One significant relation emerged, between number of appointments and quality of personal relationships (t = 2.33, p < 0.02). Those making more appointments reported more problems with the latter. Interaction effects of TA with effort and the performance variables were all negligible.

DISCUSSION Despite the small sample sizes and rather low response rates, the results were relatively clear and consistent; where hypotheses were not confirmed the results were unequivocally non-significant. There was no support for the first hypothesis. The marginally significant relations between TA and effectiveness found in Study 1 were strongly supported in Study 2. High anxious subjects, surprisingly, produced higher CV and sales closed and also greater effort. Furthermore, no indications emerged of any differences in performance efficiency associated with TA. Hence, although the more anxious group seemed to exert greater work effort than less anxious counterparts, they were no less efficient and as a result of the extra effort they tended to achieve higher results. The second and third hypotheses compared effort and Trait Anxiety as predictors of stress and of inter-personal relationship problems. Trait anxiety emerged as easily the most significant predictor in the first case in both studies, but was related to problems in personal relationships only in the first study, where the question tapped only adverse effects. The simple rating of quality of relationship in the second study did not match this result. Therefore, while anxious subjects were more effective at their work than non-anxious colleagues, owing to expending greater effort, they simultaneously reported more stress and greater effect of work on the home-work interface (in Study 1 only) and these effects did not appear to be closely related to the greater effort they expended. This raises several questions. Why does good performance not allay the anxiety of subjects high in TA? Would reducing their anxiety also reduce performance? What type of intervention might be effective-one directed at the individual or modification of the environment? At stake is the difficulty of convincing individuals that it may be their personality make-up, more than environmental circumstances, that is causing them to feel stressed. Although TA proved to be a significantly greater predictor of stress than indices of effort, it is not possible to rule out subjective interpretations of effort or differences in levels of reporting as contributory factors. This possibility is consonant with the biasses typical of subjects high in TA, which have been found in laboratory studies (see above). It may be that anxious subjects undervalue their own performance relative to less anxious colleagues, resulting in a spiral of increased effort, higher output, and additional stress. This possibility should be addressed in future research. Little support was obtained for the laboratory-generated cognitive model of trait anxiety on which the first hypothesis was based (see MacLeod, 1990). Although high anxious subjects exerted greater efforts, the reduction in efficiency levels did not approach statistical significance. It may be that the theory is simply incorrect and that efficiency is unrelated to TA. Alternatively it is highly likely that efficiency as measured in the present study does not reflect the same processes as “online” cognitive processing efficiency, but is related to a variety of other factors, such as distribution of effort over time. The opportunity for compensatory coping in naturalistic settings is greater than in laboratory situations, thus obscuring cognitive processing differences. It might be illuminating to develop laboratory tasks which resemble the natural situation in this respect. A further difference between laboratory studies and the situation of our subjects lies in the motivational aspects of the work situation. The motivation of anxious subjects, who are by definition worried about the future, may lead to greater effort and higher earnings as an insurance against the expected “rainy day”, while incentives in the laboratory are much less tangible. REFERENCES Brief, A. P., Burke, M. J., George, J. M. Robinson, B.S. & Webster, J. (1988). Should negative affectivity remain an unmeasured variable in the study of job stress. Journal of Applied Psychology, 73, 193498. Chen, P. Y. & Spector, P. E. (1991). Negative Affectivity as the underlying cause of correlations between stressors and strains. Journal of Applied Psychology, 76, 398407.

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