Avoidant personality trait: A predictor of night work adaptability?

Scott A. Davies
Missouri Western State College
November 16, 1995

Abstract

Seventy eight steel workers at a Midwestern US steel mill participated in this correlational study designed to identify a stable predictor of night shift work satisfaction. The relationships between personalities of workers, the shift they work, and job satisfaction were examined. Past research has shown that night shift workers report lower job satisfaction and a higher incidence of social and physiological problems than do day shift workers, and that a predictor of ability to adapt to night shift work needs to be identified. A sample of workers from each shift completed questionnaires measuring avoidant personality trait, global job satisfaction, and component job satisfaction. The data from the three scales were correlated with the shift the subject worked and how long he had been on that shift. A significant negative correlation (r=-.45) was found between the length of time on the shift and job satisfaction. No other significant correlations were found. In addition, a multiple regression was calculated to determine if global job satisfaction could be predicted from avoidant personality trait. Avoidant personality trait was not a significant predictor. Contrary to expectations, night shift workers were significantly more satisfied (global scale) than day shift workers (t(56)=2.47, p < .02). Because of this unusual finding, other variables may be interacting with personality trait in establishing night shift satisfaction. Future research should attempt to identify these variables.

Avoidant personality trait: A predictor of night work adaptability?

The incidence of mental and physical illness is higher among night shift workers than among day shift workers and they consistently report lower job satisfaction (Muchinsky 1993). According to Folkard, Monk and Lobban (1979), there are individual characteristics affecting a worker's ability to adapt to night work. Health problems may be the result of not properly matching workers, by their characteristics, with the shift they are assigned to work. By identifying stable characteristics that are predominate in the workers who adapt most readily to night work, and using this information as a scheduling tool, the health problems of the workers may be partially alleviated. Muchinsky reports that some people prefer to work nights, and the solution may lie in personnel selection (1993). A stable indicator of night work adaptability needs to be found.

Wedderburn (as cited in Iskra-Golec, 1993), suggested that the relationship between attitude to shiftwork and dislike of irregular hours of daily activity due to shiftwork might be associated with fundamental personality differences. The Eysenck Personality Scale (1963), has been used repeatedly when looking for correlations between personality and night work adaptability. Adams, Folkard and Young (1986), Akerstedt and Torsvall (1981), Barton (1994), as well as Bohle and Tilley (1989), used the Eysenck scale in their research, and have found mixed results in predicting night work adaptability.

In each of these studies mention is made of the difference in the perceived (by the worker), importance of social activities; and how this seems to covary with which shift a particular subject worked. This agrees with findings from informal interviews conducted over the past two years of day shift workers, night shift workers and factory supervisors. The characteristic necessary for identifying night shift adaptability may be represented by a personality construct theorized by Millon and reviewed in his 1991 paper: avoidant personality. If it is measured as Leonhard's personality accentuation (Tyrer, 1988): "in 1968 he first used this term to identify the area between normal personality and personality disorder;" then it could be measured on a continuum with no specific boundaries at the end of normal personality or the start of disorder. The ability to function in all but certain social conditions may be the unit of measure for this scale.

I propose to conduct a correlational study examining the relationship between the personality accentuation of workers and the shift they work. Based on past research, the study will focus specifically on a relationship between satisfied night workers and avoidant personality. I predict that satisfied night shift workers will score higher on a scale measuring avoidant personality than will equivalent day workers.

Methods

Subjects

Data were collected from 78 workers from one division of a Midwestern US steel foundry. This sample was representative of the 124 persons employed there. For each of the three fixed shifts, there was an approximately equal ratio of respondents to total workers per shift. There were 35 subjects from the day shift (600 to 1400 hours), 19 from the second shift (1400 to 2200 hours), and 24 from the third shift (2200 to 600 hours). The mean age of first shift workers was 39.95 years with a range of 33. The ages of the youngest and oldest subjects from first shift were 23 and 56 years, respectively. The mean length of employment with the company for first shift workers was 161.56 months. Their average time on first shift was 108.25 months. The mean age of second shift workers was 32.16 years with a range of 40. The ages of the youngest and the oldest subjects were 21 and 61 years, respectively. The mean length of employment with the company for second shift workers was 65.74 months. The average length of time on second shift was 43.24 months. The mean age of third shift workers was 34.69 with a range of 34 years. The ages of the youngest and oldest subjects from third shift were 21 and 55 years, respectively. The mean length of employment with the company for third shift workers was 58.43 months. Their average time on third shift was 40.19 months. All of the subjects were males and deemed to be in reasonably good health by their employer.

Materials

The survey I used to measure the construct of avoidant personality was designed by myself for this purpose. It is composed of 14 direct, forced choice questions. The questions were based on the seven criteria for avoidant personality disorder presented in the DSM-III R (APA 1987). It has been tested for internal reliability and is currently being tested for convergent and divergent validity as a function of this project. After the data were collected for assessing correlations, a second test measuring the avoidant personality construct was given and the validity of my scale is being checked against these results. The Faces Scale of job satisfaction (Kunin, 1955), and a portion of the Minnesota Satisfaction Questionnaire (Muchinsky, 1993), were used to assess the job satisfaction of the subjects.

Procedure

The survey, including the avoidant personality scale, two job satisfaction scales, and seven demographic questions was presented to all of the first and second shift employees during their lunch break. Instructions for completion were given and the surveys were retrieved at the end of the lunch period. The third shift employees were given their surveys at the beginning of their shift and returned them the following day. The subjects were categorized by their responses to the job satisfaction scales, the shift they work and how long they had been on that shift. These categories were correlated with the scores from their avoidance scales.

Results

The night shift workers were found to be significantly more satisfied than the day shift workers A t test with 56 degrees of freedom and with alpha set at .02 gave a t of 2.47 (t(56)=2.47, p < .02). All of the first shift employees responded that they preferred to work first shift. Five of the third shift workers responded that they would rather work first shift, 1 would rather work second shift and the remaining 17 workers responded that they preferred to work third shift. Nine of the second shift employees prefer working second shift. The remaining ten would prefer to work first shift. There was a significant negative correlation (r=-.45) found between length of time on the shift and job satisfaction. No other significant correlations were found. A multiple regression indicated that a high score on the avoidant personality trait scale did not predict night shift satisfaction.

Discussion

The higher job satisfaction of the night shift workers compared to the day shift workers is contrary to previous research findings. This may have been a factor in the absence of a significant correlation between working third shift and a high avoidant personality trait score. It is also possible that all of the employees of this plant have a strong avoidant trait, as the result of working in this environment or from a selection bias on the part of the employer's hiring process, and a similar study conducted in another work environment would produce different results.

According to the survey results, the majority of the workers prefer to work the hours that they were working at the time of this study. This could be due to social or economic factors, or it may be due to individual characteristics. The effects of the social and economic variables may be so strong in this particular group that the influence of individual characteristics, although very important, is hidden.

The results of this study were partially dependent on the validity of the avoidant personality scale that I designed. Since no significant correlations were found using this scale, the study could be redesigned utilizing another measure of avoidant personality. It is also possible that this is not the key personality trait to use to identify night shift adaptability. Other traits may be identified by further work in this area. The latest research (Barton, 1994), shows the existence of a social support variable in determining night shift adaptability. This may interact with the personality variable, for the social support one receives is often dependent on the social system that the person has constructed; and the design of the social system may covary with the person's personality.

References

Adams, J., Folkard, S., & Young, M. (1986). Coping strategies used by nurses on night duty. Ergonomics 29, 185-196.

Akerstedt, T., & Torsvall, L. (1981). Shift work: Shift-dependent well-being and individual differences. Ergonomics, 24, 265-273.

American Psychiatric Association. (1987). Diagnostic and statistical manual of mental disorders, (3rd ed. Rev.). Washington, DC: Author.

Barton, J. (1994). Choosing to work at night: a moderating influence on individual tolerance to shift work. Journal of Applied Psychology, 79, 449-454.

Bohle, P., & Tilley, A.J. (1989). The impact of night work on psychological wellbeing. Ergonomics, 32, 1089-1099.

Eysenck, H.J. and Eysenck, S. B. G., (1963). The Eysenck Personality Inventory, London: Hodder & Stoughton.

Folkard, S., Monk, T. H., and Lobban, M.C. (1979). Towards a predictive test of adjustment to shift work. Ergonomics, 22, 79-91.

Iskra-Golec, I. (1993). The relationship between circadian, personality, and temperament characteristics and attitude towards shiftwork. Ergonomics, 36, 149-153.

Kunin, T., (1955). The constuction of a new type of attitude measure. Personnel Psychology, 8, 65-67.

Millon, T. (1991). Avoidant personality disorder: A brief review of issues and data. Journal of Personality Disorders, 5, 353-362.

Muchinsky, P. (1993). Psychology Applied to Work (4th ed.). Pacific Grove: Brooks/Cole.

Tyrer, P. J. , (Ed.) . (1988) . Personality Disorders: Diagnosis, Management and Course. Essex: Butterworth.

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