Substantive & Methodological Problems in the Study of Stress at Work!
Overview • Introduction • The Big 5 Substantive & Methodological Challenges in Organizational Stress Research • 2.1 Overlap (Conceptual & Measurement) • 2.2 Confoundedness (Congeneric & Measurement) • 2.4 Change(Intraindividual & Interindividual) • 2.3 Directedness(Reversed & Reciprocal) • 2.5 Time (Longitudinal & Shortitudinal) • 3. Take Home Messages
Why this topic Introduction Demonstrating and understanding causal relations = Central aim of work and organizational psychology research on stress Experimental designs are frequently impossible to implement. Circumventing problems associated with non-experimental designs along two pathways:1) Substantive considerations tailored to W&O stress research2) Methodological considerations useful for various content domains
Why this topic Introduction (Kenny, 1979) Three commonly accepted conditions must hold for a scientist to claim that X causes Y:1. Time precedence2. Relationship3. Nonspuriousness Experiment1. The DV is measured after the IV is established2. Systematic variations in the DV conditional upon the IV3. Participants are assigned to the IV by random
Why this topic Introduction (Kenny, 1979) Getting Rid of the Relationship Condition + .25 StressReaction Stressor r = +.25 + .50 - .50 + (+.50 * -.50) = +.25 - .25 = 0.00 ThirdVariable Suppres-sor Mediator
The Content of the Subsequent Presentation Introduction What - substantive (i.e. related to the content) and- methodological (i.e. related to design and analysis) considerations are worthwhile in order to establish- time precedence (i.e. the ordering of IV and DV) and- nonspuriousness (i.e., rejection of third variable explanations) among - variables in work and organizational stress research allowing for- causal explanations? => let’s go ahead
Overlap Conceptual& MeasurementOverlap
Overlap Two Questions Addressed in this Section • How should stress and related concepts be defined? • How should stress and related concepts be measured?
Defining „Stress“ Overlap • Defining Stress • - stimulus/situation based • - reaction/person based • - transactional • Examples: • - Kobasa (1979): Stressful life events cause changes in, and demand readjustment of, an average person’s normal routine. • - Selye (1936): Stress is the body’s nonspecific responseto a demand placed on it. • - Lazarus (1966): Stress occurs when an individual perceives that the demands of an external situation are beyond his or her perceived ability to cope with them.
Defining „Stress“ Overlap • Problems with Stimulus-based Definitions of Stress • - no possibility to describes qualitatively different types of stress on the same scale (e.g., relocating and divorcing) • - no model available to allow combinations of different types of stress • - no consideration of interindividual differences in stress appraisal • - no consideration of interindividual differences in responses to stress • - everything might be regarded as stress response (even a non-response) • Problems with Response-based Definitions of Stress • - no universal stress response pattern identified yet- if universal stress responses existed, their meaning were probably not unique (e.g., blood pressure due to fear vs. joy vs. exercise)
Defining „Stress“ Overlap • Solutions:- Probabilistic model: “Average” person; (cf. Holland’s 1986 fundamental problem of causal inference and his concept of average causal effects): Stressors represent stimuli that cause stress reactions, on average- Different conceptual perspectives: + Defining a processes versus + Defining variables- Different terms: + stressor (or demand – take care!) + resources + stress reaction (strain)
Defining „Stress“ Overlap • Example: Work-Family Conflict (Stressor, Stress, Stress Reaction, Resource, Process)?Work-family conflict is a form of interrole conflict in which the role pressures from the work and family domains are mutually incompatible in some respect. That is, participation in the work (family) role is made more difficult by virtue of participation in the family (work) role. (Greenhaus & Beutel, 1985)
Measurement of „Stress“ Overlap • The exact definition of a variable represents a prerequisite for developing adequate measures. • Exercise: Develop 1-2 items in order to measure the following:- family role-pressure- work role-pressure- mutual incompatibility- difficulty- participation in the work role- participation in the family role • Definition: Work–family conflict is a form of interrole conflict in which the role pressures from the work and family domains are mutually incompatible in some respect. That is, participation in the work (family) role is made more difficult by virtue of participation in the family (work) role
Measurement of „Stress“ Overlap • Examples:Carlson, Kacmar, & Williams (2000): Due to all the pressures at work, sometimes when I come home I am too stressed to do the things I enjoy.Netemeyer Boles, & McMurrian (1996): I have to put off doing things at work because of demands on my time at home.Carlson, Kacmar, & Williams (2000): I am often so emotionally drained when I get home from work that it prevents me from contributing to my family.Haun & Dormann (2008): I feel I have not enough time for both my work and my private life.Haun & Dormann (2008): To what extent is your work life (nonwork life) to blame, when you encounter problems reconciling your work and your nonwork life? • What do these items actually measure? • What are potential problems?
Avoiding Overlap Overlap • ConclusionWe have to define non-overlapping concepts and measure them without overlap in order to avoid obtaining trivial (i.e. spurious) relations! • Solutions- Measuring stressors, resources, stress reactions objectively (take care!) => The End of this Section- Measuring (adequately!!) confonding variables and controlling (i.e., partialling) them: => The Transition to the Next Section
Objective Measurement of „Stress“ Overlap • Conceptions of Objective Stressors and Resources: • 1) Measurement without psychological processes involved => problem then: psychological stressors and resources can never be objective (only useful for material objects and processes) • 2) not illusory or unreal => problem then: the concept of objectivity is too broad (everything not illusionary) to be useful. Applies only when psychopathological phenomena are proposed • 3) not being related to a specific individual's cognitive and emotional processes (perceptions, appraisals etc). => problem then: concepts such as “average person” is required to conceptually leave out “individual” cognitive processes.
Ways to Measure „Stress“ Objectively Overlap • Measuring stress-variables that are unrelated to one specific individual's cognitive and emotional processes (perceptions, appraisals etc): • independent observers (i.e., randomly assigned) => several problems enumerated on the next slides • descriptive instead of evaluative items=> more or less easy to develop, amount of objectivity unclear • dependent observers (e.g., colleagues, supervisors, spouses)=> difficult to obtain, and amount of objectivity unclear. For example + colleagues use their own (related) working conditions to infer the level of stress reactions of the target’s stress reactions + halo errors of supervisors (e.g., an attractive subordinate feels excellent even though he was given the most demanding tasks) + similarity in personality characteristics (e.g., N or NA) of spouses cause similar biases in measurement (e.g., my wife’s time pressure is very high; my wife feels poor)
Objective Measurement of „Stress“ Overlap • Problems with observer ratings: • 1) Limited time of observation (work shift, work cycles, any kind of cycle) • 2) Unobservability of mental processes (e.g., high concentration) • 3) Effects of observation on work behavior • 4) Representativeness of workplaces (sampling frequently restricted to good/typical workplaces/hours etc) • => Conservative estimates:All of these four reasons lead to a decrease of the correlation between observed stressors and stress reactions (compared with the true correlation). Reason: The true variance of stressors is underestimated. (Frese & Zapf, 1988)
Objective Measurement of „Stress“ in Questionnaires Overlap • Note: Any kind of 'subjective' questionnaire report can be placed somewhere on a dimension from 'low in dependency on cognitive and emotional processing' to 'high in dependency on cognitive and emotional processing. • Examples: • Time Pressure: - How frequently do you have to skip regular breaks because of high time pressure? + The time pressure at work makes me feel fatigued. • Social Support: - When I have too meet tough deadlines I can count on my colleagues. + My colleagues are very responsive when I need help • Burnout: - Working all day is really a strain for me. + I have headaches. (Frese & Zapf, 1988)
Objective Measurement of „Stress“ in Questionnaires Overlap obj./perc. Resource WellBeing PerceivedStessor ObjectiveStressor Well Being Enhancement Appraisal Options Coping Options Stressor Reduction Appraisal Coping
Measurement of „Stress“ Overlap • There ain’t such thing as method variance without variance in the method. Since we usually do not vary our method of data gathering between individuals (e.g., some using questionnaires and others being observed), we better should not speak of method variance. • The things we are really talking about are psychological or psycho-physiological variables, which vary between individuals and impact on the variables as they are measured. These psychological or psycho-physiological variables have been labeled measurement-confounding variables. • When these psychological or psycho-physiological variables would impact on the variables irrespective of how they were measured, they represent congerneric confounding variables (what we usually call third variables). • Sometimes it is difficult to decide whether a confounding variable represents a measurement confounder or a congenenic confounder (e.g. negative affectivity, NA) => let’s go for the next section
Overlap Three Questions Addressed in this Section • What does confounding and related terms (spuriousness, third variable-effects) mean? • By which mechanisms are relations among IVs and DVs confounded? • How to control for confounding?
Confounding (Third) Variables Confoundedness • Several so-called ‘third variables’ can be distinguished. • A confounding variable (CV) is a variable that meets three conditions:- Cond. 1: The CV must cause the independent variable (IV) - Cond. 2: The CV must cause the dependent variable (DV) - Cond. 3: The product of the two effects must be identical to the sign of the causal effect the IV has on the DV. • A suppressor variable (SV) is similar to a confounding variable. Condition 3 is different, however:- Cond. 3: The product of the two effects must be opposite to the sign of the causal effect the IV has on the DV. • A third variable in general terms is a variable, for which Condition 3 does not have to apply, and for which one out of the two first conditions can be relaxed:- Cond. 1/2: The CV is either correlated with the IV or with the DV.
Types of Third Variables Introduction Mo-derator + StressReaction Stressor + + +-+- -+ + + +- -++- ≠ 0 ≠ 0 Con-founder Con-founder Me-diator ThirdVariable Suppres-sor
Confounding (Third) Variabls Confoundedness • “One of the factors that complicates efforts to understand method effect variables is that they may have both methodological and substantive roles" (Williams, Gavin, & Williams , 1996, p. 88)
Confounding (Third) Variabls Confoundedness • Measurement Confounding Mechanisms: • - affect priming-model: An individual’s emotional state elicits affect-congruent memories, which in turn influence his or her questionnaire ratings. • - affect as information-model: Individuals become aware of their current affect as a reaction elicited by questionnaire items. They regard their affective state as an indication about how they feel regarding the item content. (cf. Brief, Butcher and Robertson, 1995)
Confounding (Third) Variabls Confoundedness • Congeneric Confounding Mechanisms: • instrumental/stressor-creation mechanism: Individuals high in NA exhibit behavior, which leads to situations with more stressors. • selection-mechanism: Individuals with high NA may select themselves (or are selected) for jobs with more stressors. (e.g., Spector, Zapf, Chen, & Frese, 2000)
Confounding (Third) Variabls Confoundedness • Congeneric Confounding Mechanisms: • - perceptual/hyper-responsivity mechanism: Individuals with high NA perceive more stressors and more strain. NA enhances stressor perception and strain perception. (Strictly speaking, this mechanism applies to neither the measurement-confounding nor the congeneric model because NA is supposed to affect the relation between stressors and strains, but neither the constructs themselves nor their measurements. Instead, this model implies an interaction between “objective” stressors and strains on the one hand and NA on the other). (Schaubroeck, Ganster, & Fox, 1992; Spector, Zapf, Chen, & Frese, 2000; Watson & Clark; 1984; Watson & Pennebaker, 1989)
Confounding Congeneric Model Overlap Item 1 Item 2 Item 3 Item 1 Item 2 Item 3 (Williams et al., 1996) + .25 Stress-reaction Stressor r = + .25 + .50 * .50 = + .50 *) *)when analyzed without controlling for congeneric confounding variable. + .50 + .50 Congen. Conf.
Confounding Measurement Model Overlap Item 1 Item 2 Item 3 Item 1 Item 2 Item 3 (Williams et al., 1996) Stress-reaction + .50 Stressor Meas. Conf. r = + .625 *) *)when analyzed without controlling for measurement confounding variable. + .25
Pseudo-Confoundedness Confoundedness • Take Care:Beware of a logical fallacy: Even if partialling NA would reduce the stressor-strain relations, this does not prove that NA actually confounded the relationship. • Explanation: A common confounding variable exists (meta confounder), which does not only affect stressors and strains, but NA (or any other supposed third variable), too. • Mechanims: - mood mechanism - causality mechanism
Pseudo-Confoundedness Confoundedness • Mood MechanismA measurement-confounding model of mood: Mood does not only affect measures of stressors and strains, but also measures of NA. Therefore, partialling NA will reduce stressor-strain correlations, even though NA is not the confounding variable. • Causality Mechanism • NA does not affect stressors; it is just the other way round.
Meta Confounding Measurement Model Overlap Item 1 Item 2 Item 3 Item 1 Item 2 Item 3 Stress-reaction Stressor Meta Conf. Pseudo Conf. Item 1 Item 2 Item 3
Controlling for Confounding (Third) Variables Overlap • Usually, explicit measurement and control of confounding variables is required to avoid biased estimates of causal relationships. • Controlling for congeneric confounding variables is straightforward. Multiple (hierarchical) regression analysis, ANCOVA, structural equation modeling etc. • Controlling for measurement confounding variables is more demanding:- avoid measurement overlap- structural equation modeling • Some confounding variables can be explicitly (or are implicitly) controlled when change is analyzed • => let’s go for the (quite complex) next section
Change Interindividual& IntraindividualChange
Change Three Questions Addressed in this Section • Should Interindividual Differences be used to substitute for Intraindividual Change? • Should difference-scores be used as measures of change? • Could change be used to control for confounding variables?
Change Why is it worth to look at change? Cross-sectional analysis is based on some doubtful assumptions: All men were created equal and any difference is due to change. All men once had identical job conditions, and any difference … All men once suffered from identical complaints, and any difference … From this it follows: 1) Any current value of a variable can be interpreted as a change-score. 2) The relationship between two variables informs about how change in one variable caused a change in the other variable. When the assumptions do not apply, then: Potential confounders are not controlled appropriately. Appropriately addressing change may help controlling confounders.
Change The Seven Commandments of Animal Farm • 1) Whatever goes upon two legs is an enemy. • 2) Whatever goes upon four legs, or has wings, is a fried • 3) No animal shall wear clothes.
Change The Seven Commandments of Animal Farm • 4) No animal shall sleep in a bed. • 5) No animal shall drink alcohol. • 6) No animal shall kill another animal.
Change The Seven Commandments of Animal Farm • 7) All animals are created equal.
Change The Seven Commandments of Panel Farm • 1) Whatever goes upon two legs is an enemy.1) Whatever goes not beyond one measurement occasion is an enemy. • 2) Whatever goes upon four legs, or has wings, is a fried2) Whatever goes beyond one measurement occasion, or is an experiment, is a friend. • 3) No animal shall wear clothes. 3) No student shall get weary of checking results closely.
Change The Seven Commandments of Panel Farm • 4) No animal shall sleep in a bed.4) No student shall sleep at all • 5) No animal shall drink alcohol. 5) No student shall drink alcohol • 6) No animal shall kill another animal.6) No student shall kill time • - except he/she is sleeping over his/her decision to stop doing panel analysis. • - except he/she has to cope with data from more than one measurement occasion. - except has to wait for Time 2 to come (will be soon).
Change The Seven Commandments of Panel Farm • but some are more equal than others. but some students are more equal than others • 7) All animals are created equal 7) All students are created equal • and only those, who are more equal than others are allowed to use difference scores.
Change Intraindividual Change vs. Interindividual Differences Year 0
Change Intraindividual Change vs. Interindividual Differences Year 1
Change Intraindividual Change vs. Interindividual Differences Year 2
Change Intraindividual Change vs. Interindividual Differences Year 3
Change Intraindividual Change vs. Interindividual Differences Year 4
Change Intraindividual Change vs. Interindividual Differences Year 5