neuroticism: moderator or mediator in the relation between locus of control and depression?

Personality and Individual Differences 37 (2004) 245–258www.elsevier.com/locate/paid

Neuroticism: moderator or mediator in the relationbetween locus of control and depression?

Dave Clarke *

School of Psychology, Massey University, Albany Campus, Private Bag 102 904, North Shore Mail Centre, New Zealand

Received 13 February 2003; received in revised form 30 July 2003; accepted 24 August 2003

Available online 21 October 2003

Abstract

The present investigation examined empirically the influence of neuroticism on the relation between locus

of control and depression, first as a moderator with specified interaction effects, and secondly as a mediator

in the path from locus of control to depression. Levenson�s internality, powerful others and chance (IPC)

locus of control scales, the Eysencks� EPQ-R neuroticism scale and a depression inventory were completed

by 162 university students aged 17–57 years (mean¼ 27.9, SD¼ 10.3). There were no significant differences

between sexes on any mean score. Controlling for sex and age, externality, neuroticism and depression weresignificantly correlated (p < 0:001), but only chance locus of control and neuroticism predicted depression.

In the absence of significant interaction and quadratic effects, multiple regression analyses did not support

neuroticism as a moderator, but as a partial mediator in the relationship between chance locus of control and

depression. Path analysis showed that the total effect size was very large. The influence of neuroticism was

discussed in terms of the ‘‘depressive paradox’’ (self-blame and uncontrollability co-existing in depressed

individuals), the multidimensional aspects of locus of control, and implications for treating depression.

� 2003 Elsevier Ltd. All rights reserved.

Keywords: Depression; Locus of control; Neuroticism

1. Introduction

Recently the personality traits of locus of control and neuroticism have been examined togetherfor their impact on various clinical conditions (Beautrais, Joyce, & Mulder, 1999; Horner, 1996;Murray, Hay, & Armstrong, 1995; van den Heuvel, Smits, Deeg, & Beekman, 1996; Wise &

* Tel.: +64-9-414-0800x9075; fax: +64-9-441-8157.

E-mail address: [email protected] (D. Clarke).

0191-8869/$ - see front matter � 2003 Elsevier Ltd. All rights reserved.

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246 D. Clarke / Personality and Individual Differences 37 (2004) 245–258

Mann, 1993). Locus of control involves a general enduring belief in the controllability of out-comes of events in one�s life (Rotter, 1966). According to Rotter, it ranges from a belief that suchoutcomes are controllable (internal locus of control orientation or internality), to a belief thatoutcomes are generally beyond personal control (external locus of control orientation or exter-nality). Neuroticism is a personality trait that has provided a useful integrative psychobiologicalconstruct in depression research (Murray et al., 1995). Eysenck (1967) proposed that it originatesfrom the sensitivity of the limbic–autonomic nervous system that tends to be highly reactive toenvironmental and psychological stimuli. People with high neuroticism are easily startled andagitated.

For example, Horner (1996) used Rotter�s (1966) locus of control scale and the neuroticismscale of the Eysenck personality questionnaire (EPQ; Eysenck & Eysenck, 1975) with 173 com-munity dwelling adults to show that an interaction of stressful life experiences, very high exter-nality and very high neuroticism could predict reported physical illness. Neither external locus ofcontrol or neuroticism independently had a significant, direct effect on illness. For psychologicalconditions, the two variables are also salient. Murray et al. (1995) found with an all-female samplethat external locus of control of moods and neuroticism were related to seasonal affective dis-order, but extraversion, psychoticism and the EPQ Lie scale were not. Similarly, Beautrais et al.(1999) demonstrated that externality and neuroticism could reliably distinguish between youngsuicide attempters and non-attempters, but extraversion could not. In a large sample of 3107elderly participants in a Dutch longitudinal study, van den Heuvel et al. (1996) found that womentending toward externality and neuroticism reported more depressive symptoms when experi-encing various impairments in cognitive functioning. For men experiencing memory impairment,only neuroticism affected levels of depression.

There are, however, some problems with the conceptual and empirical aspects of the associa-tions between locus of control, neuroticism and depression. These problems include the ‘‘de-pressive paradox’’, the multidimensional nature of locus of control, and the functions ofmoderators and mediators.

1.1. The depressive paradox

In their meta-analysis of data from a wide range of empirical studies of the relation betweenlocus of control and depression, Benassi, Sweeney, and Dufour (1988) highlighted the ‘‘depressiveparadox’’ between two major cognitive theories of depression. Seligman�s helplessness theorypostulates that depressed people perceive events as uncontrollable, while Beck�s negative sche-matic theory implies that they have thoughts of self-deprecation and self-blame. Both theorieshave received substantial empirical support. The paradox seems to involve locus of control ori-entation because depressed individuals perceive events beyond their personal control (external),while at the same time blaming themselves for failures (internal).

A number of hypotheses have been generated to explain the paradox (Peterson, 1979). The firsthypothesis is that there is no paradox at all: depression is not related to locus of control. Anyrelationships reported might have been spurious. But Benassi et al. (1988) have clearly shown thatthere is a consistent, moderately strong relationship between external locus of control orientationand depression. Greater belief that outcomes of events are generally beyond personal control isassociated with greater depression. A second hypothesis is that there are two groups of depressed

D. Clarke / Personality and Individual Differences 37 (2004) 245–258 247

persons: one group believes in uncontrollability, the other uses self-blame. A third hypothesis isthat there are two types of outcomes: depressed persons perceive positive outcomes as uncon-trollable or resulting from luck, and blame themselves for negative outcomes. A fourth hypothesisequates self-blame with internality. None of these four hypotheses has received empirical support(Abramson & Sackeim, 1977; Benassi et al., 1988; Peterson, 1979). There is some empiricalsupport, however, for a fifth hypothesis: depressed individuals are particularly illogical in theirattributions. They have a tendency to blame themselves for events over which they perceive nocontrol. Peterson, for example, has shown with undergraduate research participants that scores onthe Beck depression inventory (BDI) were significantly and positively correlated with perceivedhelplessness and guilt simultaneously. ‘‘Almost all subjects were �illogical,� and depressives (thosewith high scores on the BDI) were particularly so.’’ (p. 623)

Although neuroticism is not explicitly mentioned in the literature, the reviews, empiricalfindings and discussions denote that the paradox and the way that externality functions mayinvolve a personality construct such as neuroticism. Because of emotional instability, a neuroticperson may have illogical attributions. Neuroticism also involves worry, guilt and preoccupationwith security (Eysenck & Eysenck, 1991). As Horner (1996) has noted, ‘‘the perception of un-controllability appears to be exacerbated for individuals who are already worried and anxious’’ (p.197). Thus, externality is an antecedent, cognitive condition that can lead to depression (Benassiet al., 1988), and neuroticism may influence at least partially that pathway from externality todepression. Internal locus of control, however, may play no role in depression.

1.2. Dimensional aspects of locus of control

All of the above studies with both neuroticism and locus of control assessed locus of controlorientation on a Rotter-based scale whereby responses are scored on one internal–external di-mension: from internality to externality. But there is some empirical evidence (Lefcourt, 1991)that locus of control is multidimensional. A person can believe to a certain degree in one�s ownability to control events while also believing that powerful others control the events in one�s life, orin the power of luck or chance happenings. Lefcourt, for example, has shown that on Levenson�s(1981) internality (I) powerful others (P ) and chance (C) (IPC) scales, while P and C weremoderately correlated with each other, correlations of the P and C scales with I ranged weaklyfrom negative to positive. Conceptually, little research has tried to understand why internality andexternality are on different dimensions, but it seems important in empirical studies to treat locus ofcontrol as a multidimensional rather than a unidimensional construct.

In their meta-analysis, Benassi et al. (1988) examined the possibility that the connection be-tween externality and depression may be due to the possibility that depressed individuals par-ticipating in research might have responded to the negativity in external locus of control itemsrather than to the external content in the items. The research that supported that possibility wasbased on Rotter�s forced-choice items. However, the relationship between externality and de-pression still existed even when Likert-type rating scales such as Levenson�s IPC scales were usedin other studies, and when forced-choice items were balanced for mood level. Rating scales do notforce respondents to choose between two items of a pair, one of which may be negative in tone.

Benassi et al. (1988) also compared the uni- and multidimensional measures of locus of control.The strength of the relationship between externality and depression was significantly weaker for


Rotter-type locus of control scales than for multidimensional scales such as Levenson�s IPCscales. It was also significantly weaker for Beck�s depression inventory (BDI) and the MMPI/depression subscale, than for the Center for Epidemiological Studies-Depression (CES-D) andZung measures of depression. Although depression is two to three times more common inwomen than in men (Davison & Neale, 2001), effect sizes were not significantly related to thepercentage of females in the studies reviewed by Benassi et al. When internality, powerful othersand chance locus of control have been investigated separately, depression was associated withpowerful others locus of control and a lack of internality (Benassi et al., 1988). More recentstudies found that chance locus of control predicted depression (e.g., Lamanna, 2001) and, in-versely, subjective well-being (DeNeve & Cooper, 1998), rather than internality or powerfulothers.

1.3. Moderators and mediators

To date, neuroticism has been considered as a moderator in the relationship between externallocus of control and depression (Horner, 1996). A variable functions as a moderator when it altersthe direction and/or strength of the effect of a predictor variable on a criterion variable (Baron &Kenny, 1986). A moderating effect is determined statistically by the presence of an interactioneffect of the predictor and the moderator on the criterion. For example, in her review of theliterature, Horner concludes that neuroticism is the most likely personality variable that mod-erates the influence of locus of control. It is stable over time and situation, and a person with highneuroticism is vulnerable to clinical conditions even when stressors are not present. She thendemonstrated that neuroticism and externality interacted in a quadratic fashion to moderate theeffects of stressors on physical illness. Only very high neuroticism and very high external locus ofcontrol in the presence of stressors predicted illness. Neuroticism and externality were not sig-nificant predictors of illness.

An alternative consideration is that neuroticism may function as a mediator in the relationshipbetween externality and clinical conditions. For example, Wise and Mann (1993) suggested pathanalysis for clarifying the nature of the mediating effect of neuroticism between locus of controland alexithymia, a clinical construct denoting a person�s inability to experience and relate emo-tional feelings, and related to depression. Because of their small number of subjects, theywere unable to do path analysis. A variable functions as mediator to the extent that it ac-counts for the relation between the predictor and the criterion (Baron & Kenny, 1986). Whereasmoderators specify when certain effects will occur, mediators explain how or why such effectsoccur.

Fig. 1 illustrates the difference between neuroticism as a moderator and neuroticism as a me-diator. In Fig. 1a, there are three causal paths that lead to depression: the influence of externalityas a predictor (Path a), the influence of neuroticism as a moderator (Path b), and the interactionof these two (Path c). The moderating effect is present if Path c is significant. Paths a and b may besignificant also, but are not directly relevant for testing moderation. It would also be expected thatN would not be correlated with both Ext and Dep to provide a clearly interpretable interactioneffect. Thus, if N is a moderator, then there would be a synergistic (multiplicative) effect on de-pression: externality and neuroticism together would account for additional variation in de-pression beyond externality and neuroticism as independent variables.

(a) Moderated Model (b) Mediated Model

Exta

N Depb

Ext x N c

N a b

Ext Dep

c

Fig. 1. Models derived from Baron and Kenny (1986) of moderated (a) and mediated (b) effects of neuroticism (N ) on

the relation between external locus of control (Ext) and depression (Dep).


In Fig. 1b, however, N would be correlated with both Ext and Dep. Mediation implies that Ext(the predictor) influences N (the mediator) which, in turn, influences Dep (the criterion variable).According to Baron and Kenny (1986):

Moderator variables are typically introduced when there is an unexpectedly weak or in-consistent relation between a predictor and a criterion variable (e.g., a relation holds inone setting but not in another, or for one subpopulation but not for another). . . .Me-diation, on the other hand, is best done in the case of a strong relation between the pre-dictor and the criterion variable (p. 1178).

Baron and Kenny have provided several guidelines for investigating empirically the effects of amediator on a predictive relationship. When individual differences such as neuroticism are in-volved, a mediator represents a property or stable characteristic of a person that transforms thepredictor variables in some way. For neuroticism to function as a mediator in the path fromexternality to depression, two conceptual relationships are assumed: (1) externality leads to de-pression, rather than vice versa, and (2) depression is not a cause of neuroticism. Support for thetwo assumptions is provided from the findings of Greenspoon and Sasklofske (2001) who dem-onstrated with a sample of 407 children that externality and neuroticism were significantly relatedto the development of internalised psychopathology. Similarly, Sumi and Kanda (2002) showed ina prospective design with 138 Japanese male college students that neurotic perfectionism was apredictor of depression, and not vice versa.

1.4. The present study

The purpose of the present investigation was to use Baron and Kenny�s (1986) criteria fortesting empirically if neuroticism has a moderating or a mediating influence on the relation be-tween externality and depression. From the literature reviewed above, several guidelines aresuggested. First, the strengths of the relationships among the variables should be measured to (a)ascertain which variables are related to depression, and (b) determine if neuroticism fulfills thedesired conditions for a moderating or a mediating effect. For (b), if the relation between ex-ternality and depression is weak or inconsistent, then a moderating effect may be present; if the


relationships among all three are strong, then a mediating effect is suspected. Secondly, themultidimensional role of locus of control as a predictor of depression should be investigatedbefore testing for moderating or mediating effects of neuroticism. Thirdly, it can be assumed thatneuroticism is the personality trait most likely to affect the relation between externality and de-pression. Fourthly, the measure of depression should be appropriate for a non-clinical as well as aclinical population.

2. Method

2.1. Sample

A class of 165 students who were enrolled in an introductory psychology course at the Albanycampus of Massey University completed the questionnaires; 162 of them provided sufficient datafor the current analyses. There were 129 women and 33 men. The age distribution was moderatelyskewed (0.94), with no outliers. Ages ranged from 17 to 57 years, with an average age of 27.9 years(SD¼ 10.3; median¼ 24). Seventy-two percent of the sample identified themselves as Caucasianor New Zealand European, 14% as Polynesian, and 9% as Asian. Most of the participants (83%)were in the average and above average socioeconomic groups. The sample thus consisted pre-dominately of young, female, Caucasian adults with moderate to high socioeconomic status.

2.2. Materials

2.2.1. Locus of controlRotter�s (1966) internal–external locus of control scale has been the most widely used and cited

measure (Benassi et al., 1988), but has been criticized extensively with regard to its presumedunidimensionality, its inherent social desirability response bias, and the difficulties and compli-cations created by its forced-choice format, such as its negatively biased items (Benassi et al.,1988; Lefcourt, 1991). The internality, powerful others and chance (IPC) scales (Levenson, 1981)consist of 24 items with three subscales corresponding to three dimensions of locus of control. Forthe present study, participants rated each item on a 7-point Likert-type scale ranging fromstrongly disagree (1) to strongly agree (7), with neutral (4) as the midpoint. In contrast to Rotter�sdichotomous measure of locus of control, Levenson�s scales provide a multidimensional measureof the concept, have no reported social desirability bias, are more statistically independent, havegood psychometric properties, and make a distinction between personal and ideological state-ments by having all items phrased in the first person as opposed to describing people in general(Lefcourt, 1991). The internality (I) scale measures the extent to which one believes that one hascontrol over one�s life. The items seem to describe the concept of self-determination (e.g., ‘‘My lifeis determined by my own actions.’’). The powerful others (P) scale concerns the belief that otherpersons control the events in one�s life (e.g., ‘‘Getting what I want requires pleasing those peopleabove me.’’). The chance (C) scale measures the degree to which one believes that fate or luckaffects one�s experiences and outcomes (e.g., ‘‘To a great extent my life is controlled by accidentalhappenings.’’). Scores can range from 8 to 56 on each scale. For the present sample, the coeffi-cients of internal consistency (Cronbach�s alpha), were 0.63 (I), 0.74 (P) and 0.82 (C).


2.2.2. Neuroticism

The neuroticism (N ) scale was selected from the revised Eysenck personality questionnaire(EPQ-R; Eysenck & Eysenck, 1991) to measure the trait of emotional instability, worry and guilt.Scores range from 0 to 24. Cronbach�s alpha for the group was 0.76.

2.2.3. DepressionThe depression symptom inventory was developed from previous research (Bell, LeRoy, &

Stephenson, 1982) with medical inpatients and outpatients, and cross-sectional studies such as theStirling County and the Midtown Manhattan surveys to ascertain levels of depression in thecommunity. It was used rather than the Beck depression inventory (BDI; Beck, Ward, Mendelson,Mock, & Erbaugh, 1961) because the BDI was designed to assess the severity of depression in aclinically diagnosed group (Davison & Neale, 2001), whereas the depression symptom inventory isalso applicable for a non-clinical population. Each item is rated on a five-point scale, from‘‘often’’ to ‘‘never’’, with a maximum score of 72. For the present study, item one was re-wordedfrom ‘‘Do you feel in good spirits?’’ to ‘‘Do you have a feeling of well-being?’’, to avoid M�aoriconnotations relating to the spirits of their ancestors; and item 18 from ‘‘How does the future lookto you?’’ to ‘‘Does the future seem uncertain to you?’’ to make sense in terms of the rating scale.The modified depression scale had an internal consistency coefficient of 0.83 for the presentsample.

2.3. Procedure

The strengths of the intercorrelations were assessed by Pearson correlation coefficients. A si-multaneous regression analysis was undertaken to determine the unique contribution of eachvariable in the prediction of depression. With the significant predictor variables, the analyses thentested whether neuroticism assumed the role of moderator or mediator in the relation betweenexternality and depression. For the moderating effect of neuroticism, hierarchical regressionanalysis tested for linear, quadratic and interaction effects on the relation between externality anddepression, as suggested by Baron and Kenny (1986). The order of entry was externality, neur-oticism (N), their interaction (externality ·neuroticism), and the quadratic terms (N 2 andexternality� N 2). Quadratic effects were examined because Horner (1996) in her conclusionssuggested that nonlinear aspects of personality may be more salient for illness research than linearones. Before testing for the interaction effects, the scores on the appropriate IPC scales and N were‘‘centered’’ by subtracting their respective sample means from all individuals� scores, thus pro-ducing revised sample means of zero. The procedure, suggested by Aiken and West (1991), was toeliminate the possible effects of multicollinearity between first order terms of the main effects andthe higher order interaction and quadratic terms.

To test for the mediating effect of neuroticism in the relation of externality to depression, threeregression equations must be computed and four conditions must be met (Baron & Kenny, 1986).For the variables in the present study, the three regression equations are:

(1) Neuroticism¼B1Externality +Control Variables,(2) Depression ¼ B2Externality +Control Variables,(3) Depression ¼ B3Externality +B4Neuroticism+Control Variables,


where Bs represent the unstandardised regression coefficients. With these three equations, the fourconditions are: (a) B1 must be significant; (b) B2 must be significant; (c) B4 must be significant; and(d) B3 must be smaller than B2. If B3 is reduced to a non-significant effect, full mediation isdemonstrated. If B3 is reduced, but still significant, then partial mediation is demonstrated. If amediating effect is present, then path analysis would be conducted to estimate the direct andindirect effects of externality on depression, with neuroticism as the mediating variable (Pedhazur,1997).

3. Results

Prior to inferential analyses, the data for each scale were examined for outliers and for as-sumptions of normality. For the IPC and N scales, and the depression inventory, the distributionsof data were within the normal ranges and raw data were used in the computations. The level forsignificance was set at p < 0:001 for a conservative estimate of the significance of relationshipsamong the variables. A one-way MANOVA revealed no significant differences between men�s andwomen�s mean scores on the IPC locus of control scales, Neuroticism and depression, Wilks�lambda¼ 0.94, F ð5; 157Þ ¼ 2:04, p > 0:05. Therefore, men�s and women�s data were combined forsucceeding analyses.

3.1. Intercorrelations

The intercorrelations among the variables, their means and standard deviations are shown inTable 1. The zero-order correlations appear below the diagonal; partial correlations in which theeffects of sex and age have been controlled are above the diagonal. As depicted in Table 1, therewas almost no change in significance or value after controlling for sex and age. Depression wassignificantly related to powerful others locus of control (r ¼ 0:35), chance locus of control(r ¼ 0:47) and neuroticism (r ¼ 0:63). Neuroticism significantly correlated with powerful othersand chance locus of control (r ¼ 0:33, each). The two external locus of control variables, powerfulothers and chance, were strongly correlated (r ¼ 0:70).

Table 1

Means, standard deviations and correlations for Levenson�s IPC locus of control scores, Eysenck neuroticism scale

scores and depression inventory scores (N ¼ 162)

Variables 1 2 3 4 5

Internality – )0.02 )0.22 0.04 )0.01Powerful Others )0.03 – 0.70* 0.32* 0.36*

Chance )0.23 0.70* – 0.33* 0.47*

Neuroticism 0.00 0.33* 0.33* – 0.64*

Depression )0.02 0.35* 0.47* 0.63* –

Mean 40.42 24.67 25.19 10.59 27.09

SD 5.68 6.82 7.76 5.74 9.45

*p < 0:001.Pearson product–moment correlations appear below the diagonal; partial correlations controlling for sex and age,

above the diagonal. All tests are two-tailed.


Internality was not significantly related to any of the other variables. A simultaneous regressionanalysis with I , P , C and N as predictors of depression revealed that only C ðb ¼ 0:35Þ andN ðb ¼ 0:54Þ accounted for significant, unique variance in depression scores, F ð4; 158Þ ¼ 36:11,p > 0:001. Internality (b ¼ 0:06) and powerful others locus of control (b ¼ �0:07) contributednegligibly (p > 0:05), and were thus omitted in the tests for moderating and mediating effects onthe relation between externality and depression. The purpose of the present investigation was toascertain the unique contribution and importance of the predictor variables on depression. Al-though P correlated moderately with depression (r ¼ 0:35), it was not included in testing for themoderating and mediating effects, because of its multicollinearity with C and hence instability andproblematic interpretation of the results of multiple regression analysis (Polit, 1996, Chap. 4).

3.2. Moderating effects of neuroticism

Table 2 presents the results of hierarchical regression analysis for the main, interaction andquadratic effects on depression. Only the main effects, chance locus of control (b ¼ 0:27) andneuroticism (b ¼ 0:52), remained significant at each step, accounting for unique variance in de-pression scores, before and after the introduction of the interaction and quadratic terms. Chancelocus of control accounted for 7% and neuroticism 29% of the variance in depression scores.

3.3. Mediating effects of neuroticism

The first step in testing the mediating effect of neuroticism was to demonstrate that chance locusof control is significantly related to neuroticism. The zero-order correlation of 0.33 noted in Table1, after controlling for sex and age, provides initial support for this effect. The results of the re-gression analyses predicting depression as a function of chance locus of control and mediated byneuroticism appear in Table 3. All four of the conditions specified by Baron and Kenny (1986)were met at or beyond the 0.001 level of significance: (a) chance locus of control significantlyaccounted for variations in neuroticism (B1 ¼ 0:25), F ð1; 161Þ ¼ 29:47, (b) the relationship be-tween chance locus of control and depression was initially significant (B2 ¼ 0:57),F ð1; 161Þ ¼ 44:91, (c) neuroticism significantly accounted for variations in depression (B4 ¼ 0:88),F ð2; 160Þ ¼ 71:84, and (d) with neuroticism in the equation, the unstandardised regression coef-ficient for chance locus of control on depression was smaller than B2 (B3 ¼ 0:35). Further, because

Table 2

Results of hierarchical regression analysis of powerful others locus of control, chance locus of control, neuroticism,

interaction and quadratic effects on depression (N ¼ 162)

Variable (R2 ¼ 0:48) B SE B b Partial R2 F at entry

Chance 0.33* 0.09 0.27 0.07* 44.91*

Neuroticism 0.86* 0.11 0.52 0.29* 71.84*

Chance · neuroticism )0.01 0.01 )0.05 0.00 47.67*

Neuroticism2 0.01 0.02 0.04 0.00 35.77*

Chance · neuroticism2 0.00 0.00 0.04 0.00 28.51*

Intercept 27.52* 2.62

*p < 0:001.

Table 3

Summary of regression analyses for direct and indirect effects of chance locus of control on depression via neuroticism

(N ¼ 162)

Variable B SE B b Partial R2

Regression of neuroticism on chance locus of control (R2 ¼ 0:11)Constant 4.39 1.45

Chance 0.25* 0.06 0.33 0.11

Regression of depression on chance locus of control (R2 ¼ 0:22)Constant 30.77* 2.24

Chance 0.57* 0.09 0.47 0.22

Regression of depression on neuroticism and chance locus of control (R2 ¼ 0:47)Constant 26.91* 1.89

Chance 0.35* 0.07 0.29 0.12

Neuroticism 0.88* 0.10 0.54 0.33

Indirect 0.18

Spurious 0.10

*p < 0:001.


B3 was still significant, neuroticism had a partial mediating effect on the prediction of depressionfrom chance locus of control.

The results of the third regression in Table 3 show the proportion of the total effect of chancelocus of control (0.47) on depression, consisting of the direct effect (0.29) and the indirect effectthrough neuroticism (0.18). Therefore, as a mediator, neuroticism accounted for 38% of the totaleffect of chance locus of control on depression. For multiple and multiple partial correlations,Cohen (1992) has tabled a standardised measure of association (f ) which is independent of theoriginal measurement units. An f 2 of 0.35 is considered a large effect size. For the third regression,an R2 of 0.47 yields an f 2 of 0.89. Hence, the total effect of chance locus of control on depressionvia neuroticism was very large. The statistical power to detect significance at the 0.01 level was atleast 90% for large effect sizes.

0.33* 0.54*

0.29*

Note: Residuals appear incircles.

*p< 0.001

Chance Locus of Control Depression

Neuroticism

0.53

0.89

Fig. 2. Path model and standardised regression coefficients depicting the role of neuroticism in mediating the effects of

chance locus of control on depression.


Fig. 2 presents the path analysis for the mediating model (Pedhazur, 1997). The standardisedpath coefficients (b�s) show the direction and magnitude of the effects of chance locus of controland neuroticism on depression. The coefficients depicting the paths from chance locus of controlto neuroticism (0.33), from neuroticism to depression (0.54) and from chance locus of control todepression (0.29) were significant (p < 0:001).

4. Discussion

4.1. Locus of control, neuroticism, and depression

Because internal locus of control was not related to powerful others and chance locus ofcontrol, the present study provided further evidence that locus of control is a multidimensionalrather than a unidimensional construct. In contrast, powerful others and chance locus of controlwere highly correlated. The two variables could be considered as different manifestations of ex-ternal locus of control, belief that events in one�s life are controlled by factors beyond one�s in-fluence or control. Internality was also not related to neuroticism or depression. Because thecoefficient of internal consistency was the lowest of the three scales (0.63), it is possible that errorvariance could have masked the extent of the association of internality with the other variables.For example, the correlation between internality and chance locus of control ()0.23) was sig-nificant beyond the 0.01 level, above the criterion for the tests of significance in the present study(p < 0:001). The correlations with powerful others and depression were almost zero. Thus, it islikely that internality is negatively correlated with chance rather than powerful others locus ofcontrol or depression. An increase in self-determination or internality is associated with a decreasein belief in fate or luck but does not seem to affect depression.

4.2. Moderating versus mediating effects of neuroticism

The data from the present investigation provided no empirical support for the moderatinginfluence of neuroticism on the relation between externality and depression. The correlationsamong the three variables were highly significant and moderately strong, suggesting a mediatinginfluence instead. Confirmatory hierarchical regression analysis showed that in the absence ofinteraction and quadratic effects, neuroticism was not functioning as a moderator, specifyingwhen the relation is most likely to occur.

On the other hand, there was strong support for the concept of neuroticism as a mediator in thepath from externality and depression. Specifically, the component of externality that functioned inthe path was chance rather than powerful others locus of control, as found in recent studies(DeNeve & Cooper, 1998; Lamanna, 2001). Neuroticism could explain partially how chance locusof control can lead to depression: the stronger the belief that fate controls the outcomes of per-sonal events, the greater the stimulation of worry and guilt, and the deeper the depression that ismanifested (Eysenck & Eysenck, 1991; Greenspoon & Sasklofske, 2001; Sumi & Kanda, 2002).Because the relationships among the three variables were essentially the same after control-ling for sex and age, their influences seem to apply equally for both male and female adults of allages.


In contrast, Horner (1996) found that neuroticism moderated the relation between externallocus of control and physical illness non-linearly with stressors. Similarly, van den Heuvel et al.(1996) showed that neuroticism and externality moderated the relation between cognitive func-tioning and depression in older adults. However, both of these studies used unidimensionalmeasures of locus of control and did not examine mediating effects. The mediating effect ofneuroticism may be applicable only for chance locus of control leading to depression. Whetherneuroticism has an actual ‘‘causal’’ moderating or mediating effect needs to be ascertained withexperimental and longitudinal data (van den Heuvel et al., 1996). The evidence that does existfrom prospective research (Greenspoon & Sasklofske, 2001; Sumi & Kanda, 2002) suggests thatexternality and neuroticism predict depression. Yet to be demonstrated is that by introducing anuncontrollable chance event, chance locus of control stimulates people who worry, with bothchance locus of control and neuroticism leading to depression.

4.3. The depressive paradox

The paradox that individuals who perceive the outcomes of events as uncontrollable, yetsomehow still feel responsible, may be explained partially by the mediating effect of neuroticism.First, it is more likely that chance rather than powerful others locus of control leads to depression.People who perceive that the outcomes of events are due to chance or luck may try to deal withtheir feelings of helplessness neurotically with worry and guilt (Peterson, 1979). Such a reactionexacerbates the tendency of chance locus of control to lead to depression. Secondly, it is irrelevantif the outcomes are positive or negative (Benassi et al., 1988). For example, individuals whoperceive success as due to chance, may initially feel elated, but then feel guilty at succeeding whenothers have not, worry that they may not be so lucky next time, and thus become depressed.Because their nervous systems are attuned to be highly reactive to environmental and psycho-logical stimuli (Eysenck, 1967), they can react also from their own perceptions that luck or fatedetermines their successes and failures. If they believe that powerful others affect the outcomes forthem, then they are less likely to be depressed than chance believers, because they can attribute theresponsibility to other people and not feel guilt and worry about the outcomes.

According to the mediated model, if their belief in fate is changed, then both neuroticism anddepression are affected. For example, Beck�s therapies have helped depressed people break theirmaladaptive, illogical and cyclical thought patterns of negative beliefs, and hopelessness (Beck,1995). Cognitive-behavioural therapies may thus work partially through neuroticism, becauselowering belief in chance locus of control depressive symptoms may also lower the neurotic re-actions leading to depression. In a review of studies of psychotherapies for depression, Jarrett(1990) concluded that cognitive, behavioural and interpersonal therapies were effective only in theacute treatment of adult, non-bipolar, non-psychotic depressed outpatients. Hence, early inter-vention would be recommended to affect both externality and neuroticism.

Based on prospective research (Greenspoon & Sasklofske, 2001; Sumi & Kanda, 2002), it wasassumed in the present study that externality leads to depression, rather than vice versa, and thatdepression is not a cause of neuroticism. The relationships among externality (the predictor),neuroticism (the mediator) and depression (the criterion) may not necessarily be ‘‘causal’’. Ifchance locus of control, neuroticism and depression are merely covariates, then from the presentfindings, the covariance between chance locus of control and depression is diminished when


neuroticism is controlled (James & Brett, 1984). To demonstrate an actual ‘‘causal’’ mediatingeffect, longitudinal data would be required (van den Heuvel et al., 1996). For therapy, the im-plication of covariation then is that dealing with the neuroticism may be helpful in weakening thelink between chance locus of control and depression for vulnerable individuals.

Acknowledgements

This research was funded by a Massey University Research Fund grant to D. Clarke. Muchappreciation is given to Dr Ross Flett and to the reviewers for comments and suggestions on anearlier version of this article.

References

Abramson, L. Y., & Sackeim, H. A. (1977). A paradox in depression: uncontrollability and self-blame. Psychological

Bulletin, 84(5), 838–851.

Aiken, L. S., & West, S. G. (1991). Multiple regression: testing and interpreting interactions. Newbury Park, CA: Sage.

Baron, R. M., & Kenny, D. A. (1986). The moderator–mediator variable distinction in social psychological research:

conceptual, strategic, and statistical considerations. Journal of Personality and Social Psychology, 51, 1173–1182.

Beautrais, A. L., Joyce, P. B., & Mulder, R. T. (1999). Personality traits and cognitive styles as risk factors for serious

suicide attempts among young people. Suicide and Life-Threatening Behavior, 29(1), 37–47.

Beck, A. T., Ward, C. M., Mendelson, M., Mock, J. E., & Erbaugh, J. K. (1961). Inventory for measuring depression.

Archives of General Psychiatry, 4, 561–571.

Beck, J. S. (1995). Cognitive conceptualization. In Cognitive therapy: basics and beyond (pp. 13–24). New York:

Guilford Press.

Bell, R. A., LeRoy, J. B., & Stephenson, J. J. (1982). Evaluating the mediating effects of social support upon life events

and depressive symptoms. Journal of Community Psychology, 10, 325–340.

Benassi, V. A., Sweeney, P. D., & Dufour, C. L. (1988). Is there a relation between locus of control orientation and

depression? Journal of Abnormal Psychology, 97(3), 357–367.

Cohen, J. (1992). A power primer. Psychological Bulletin, 112(1), 155–159.

Davison, G. C., & Neale, J. M. (2001). Abnormal Psychology (8th ed.). New York: John Wiley & Sons.

DeNeve, K. M., & Cooper, H. (1998). The happy personality: A meta-analysis of 137 personality traits and subjective

well-being. Psychological Bulletin, 1992, 1–159.

Eysenck, H. J. (1967). The biological basis of personality. Springfield, IL: Charles C. Thomas.

Eysenck, H. J., & Eysenck, S. B. G. (1975). Manual of the Eysenck personality questionnaire. London: Hodder &

Stoughton.

Eysenck, H. J., & Eysenck, S. B. G. (1991). Manual of the Eysenck personality scales (EPS adult). London: Hodder &

Stoughton.

Greenspoon, P. J., & Sasklofske, D. H. (2001). Toward an integration of subjective well-being and psychopathology.

Social Indicators Research, 54(1), 81–108.

Horner, K. L. (1996). Locus of control, neuroticism, and stressors: combined influences on reported physical illness.

Personality and Individual Differences, 21(2), 195–204.

James, L. R., & Brett, J. M. (1984). Mediators, moderators, and tests for mediation. Journal of Applied Psychology, 69,

307–321.

Jarrett, R. B. (1990). Psychosocial aspects of depression and the role of psychotherapy. Journal of Clinical Psychiatry,

51(6), 26–35.

Lamanna, M. D. (2001). The relationships among emotional intelligence, locus of control and depression in selected

cohorts of women. Dissertation Abstracts International: Section B (Sciences and Engineering), 61(10-B), 5569.


Lefcourt, H. M. (1991). Locus of control. In J. P. Robinson, P. R. Shaver, & L. S. Wrightsman (Eds.), Measures of

personality and social psychological attitudes (2nd ed., pp. 413–498). San Diego, CA: Academic Press.

Levenson, H. (1981). Differentiating among internality, powerful others and chance. In H. M. Lefcourt (Ed.), Research

with the locus of control construct (Vol. 1, pp. 15–63). New York: Academic Press.

Murray, G. W., Hay, D. A., & Armstrong, S. M. (1995). Personality factors in seasonal affective disorder: Is seasonality

an aspect of neuroticism? Personality and Individual Differences, 19(5), 613–617.

Pedhazur, E. J. (1997).Multiple regression in behavioral research: explanation and prediction. Fort Worth, TX: Harcourt

Brace College Publishers.

Peterson, C. (1979). Uncontrollability and self-blame in depression: investigation of the paradox in a college

population. Journal of Abnormal Psychology, 88(6), 620–624.

Polit, D. (1996). Multiple regression. In Data analysis and statistics for nursing research (pp. 257–304). Stamford, CT:

Appleton & Lange.

Rotter, J. B. (1966). Generalized expectancies for internal versus external control of reinforcement. Psychological

Monographs, 80, 1–28.

Sumi, K., & Kanda, K. (2002). Relationship between neurotic perfectionism, depression, anxiety, and psychosomatic

symptoms: a prospective study among Japanese men. Personality and Individual Differences, 32(5), 817–826.

van den Heuvel, N., Smits, C. H. M., Deeg, D. J. H., & Beekman, A. T. F. (1996). Personality: a moderator of the

relation between cognitive functioning and depression in adults aged 55–85? Journal of Affective Disorders, 41, 229–

240.

Wise, T. N., & Mann, L. S. (1993). Is alexithymia distinct from health locus of control? International Journal of

Psychiatry in Medicine, 23(4), 339–347.

neuroticism: moderator or mediator in the relation between locus of control and depression?

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