Person. inckid. Difl. Vol. 6. No. 6. Pp. 737-742. 1985 Printed in Great Britain. All rights reserved

0191~8869/85S3.00+0.00 Copyright c 1985 Pergamon Press Ltd

PSYCHOTICISM, CREATIVITY DICHOTIC SHADOWING

DAVID RAWLINGS* Department of Experimental Psychology, University of Oxford,

Oxford OXI 3UD, England

(Receiced 12 February 1985)

AND

South Parks Road,

Summary-Thirty Ss were presented with pairs of words simultaneously under the instruction to shadow one ear while ignoring the other (the Focussed Attention condition) or to shadow one ear while attempting to remember the other (the Divided Attention condition). Ss also completed the Eysenck Personality Questionnaire and two tests of creativity from the Wallach and Kogan battery. It was hypothesized that Ss high on EPQ Psychoticism and on creativity should make more shadowing errors of omission and intrusion. Creative Ss made significantly more errors of intrusion under the divided attention condition, but Ss scoring high on the Similarities subtest showed significantly fewer errors in the Focussed Attention condition. An ‘impulsivity’ interpretation of the data is tentatively advanced, and it is shown how this interpretation may explain a number of the anomalous findings in the psychoticism literature.

INTRODUCTION

Criterion validation of the Psychoticism (P) scale of the Eysenck Personality Questionnaire (EPQ) has proceeded on two fronts. On the one hand, the scale has been shown to differentiate normal Ss from groups of prisoners, alcoholics and drug addicts rather better than from groups of psychotic patients like schizophrenics (Eysenck and Eysenck, 1976), a fact which led to some of the early criticisms of the scale (Bishop, 1977; Block, 1977; cf. Eysenck and Eysenck, 1977). The alternative approach has been to discover whether high P scorers perform ‘like psychotics’ on a variety of behavioural tasks. Eysenck and Eysenck (1976) do report a number of studies in which high P scorers perform in a manner parallel to the performance of psychotic groups, but these results are far from convincing. Of particular concern is the finding that high P Ss show faster reaction times than low P Ss, in direct contrast to the slowness which typically characterizes schizophrenics (e.g. Hendrickson, 1972; Thompson, 1973). Clearly, this latter approach to validation requires additional evidence to bolster the presumed relationship between psychoticism and psychosis, as well as requiring a rationale for the interpretation of inconsistent findings.

A popular view during the 1960s was that the non-paranoid schizophrenic shows a widening of selective attention which precludes him from inhibiting irrelevant stimuli (Payne, 1960; Shakow, 1963; Silverman, 1964; McGhie and Chapman, 1961; Weckowicz, 1957). Several studies aimed at the empirical investigation of this claim employed some form of dichotic listening task, such as the shadowing procedure devised by Cherry (1953) in which Ss are required to say what they hear in one ear while ignoring a simultaneous message in the other. The prediction that schizophrenics should show more errors in dichotic shadowing than non-psychiatric or non-psychotic groups, and in particular should show greater intrusion of distractor words into the shadowed material, has not always been confirmed. Schneider (1976) failed to confirm the prediction using digits, as did Straube and Germer (1979) using unrepeated word pairs. Korboot and Damiani (1976) found the prediction confirmed only for ‘delusional’ schizophrenics when the distracting material concerned the content of their delusions. However, when redundant relevant stimuli such as prose or repeated lists have been employed, group differences between schizophrenics and non-schizophrenics (Dykes and McGhie, 1976; Wahl, 1976; Wishner and Wahl, 1974) or between thought-disordered and non-thought-disordered schizophrenics (Payne, Hochberg and Hawks, 1970) haoe been found. As Straube and Germer point out, “subjects have less difficulty shadowing redundant material, so

‘Present address: Melbourne College of Advanced Education, 757 Swanston Street, Carlton, Victoria 3053, Australia.

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73x DAVID RAWLINGS

periodic switches to the irrelevant channel are more likely to occur”. The prediction has not always been confirmed under all shadowing conditions. For example, Wishner and Wahl(1974) found that schizophrenics only made more intrusion type errors than controls when asked to listen to the distractor words; that is, under ‘divided’ but not ‘focussed’ attention conditions. However, the results do give general support to the main hypothesis of the present study: that high P Ss will show a greater number of shadowing omissions and intrusions than low P Ss in a task involving repeated word-pairs.

Further support for the above hypothesis is contained in an additional finding of the Dykes and McGhie (1976) study. These investigators found that Ss who scored high on the Wallach and Kogan (1965) tests of creative thinking showed more intrusive errors than low creative Ss with word-pairs of high association value, although the number of intrusions was still considerably smaller than that shown by schizophrenics. Creative Ss were also able to recognize a significantly higher number of items on the irrelevant channel than the low creatives. Subsequently, Woody and Claridge (1977) showed that output on the Wallach and Kogan subtests was strongly and positively correlated with scores on the P scale. The above studies clearly implied that the relationship between P and dichotic shadowing was worthy of investigation. The present experiment also included two measures of creativity derived from the Kogan-Wallach battery, and differentiated word-pairs on the basis of high and low association strength as suggested by Dykes and McGhie.

METHOD

The 30 Ss (19 female, 11 male) had a mean age of 26.4 yr and were from the Subject Panel of the Oxford University Department of Experimental Psychology. Ss first completed the Eysenck Personality Questionnaire (EPQ; Eysenck and Eysenck, 1976) and the Pattern Meanings and Similarities subtests from the Wallach and Kogan battery of creativity tests, administered under untimed conditions. They were then presented with pairs of words, one to each ear simultaneously, using stereo headphones and a Sony stereo tape-recorder. The material for the shadowing task consisted of a specially prepared dichotic listening tape on which there were two lists of word-pairs. Each list was constructed from eight pairs of words which were randomly repeated eight times, presentation time being approx. 1 min. All words were of one syllable, and words in each channel were matched for length and frequency of appearance in written English (Thorndike and Lorge, 1944). Half of the word-pairs in each list represented high, and half low, degrees of association (Postman and Keppel, 1970). Shorter practice lists both with and without distractor words were constructed for inclusion before each main list.

In the first part of the experiment, the ‘Focussed Attention’ condition, half of the Ss were told to shadow with the right ear and to ignore the left; half to shadow with the left ear and ignore the right. During the practice trials, the number of errors made in the shadowing without distraction trials was recorded. The numbers of errors and omissions made in the main shadowing session were collated, as was the number of words from the irrelevant (secondary) channel which intruded into the shadowing of the relevant list. At the conclusion of the main shadowing session (but not the practice trials) Ss were given a recognition task. The 16 words used in the shadowing session and eight other words were presented on cards in a different random order to each S, and the number of words recognized was recorded.

In the second part of the experiment, the ‘Divided Attention’ condition, Ss were asked to shadow with one ear (always the same ear as in the first part of the experiment) but to also try to remember as many words as possible in the secondary channel. This task was again preceded by a brief practice session, and followed by a recognition task.

Three measures of performance in the shadowing task were calculated for each condition: the total number of errors of all kinds, including omissions, made in the shadowing task (abbreviated ‘Errors’ or ERR); the number of errors of intrusion from the non-shadowed channel (‘Intrusions’ or INTR); and the number of errors made in the recognition task, involving words from the non-shadowed channel (‘Recognition’ or REC). For each of the creativity subtests, two measures were calculated: the total number of responses made to each item (‘Fluency’), and the number of unique responses to each item (‘Originality’). The shadowing measures were related to the four personality scales and to the creativity indices using the Pearson correlation technique.

Psychoticism. creativity and dichotic shadowing 739

Table I. Correlations of shadowing variables with creativity and personality measures. sex and age (N = 30)

Focussed condition Divided condition

ERR -1NTR REC ERR INTR REC

Parrern meanings Fluency 16 -13 -09 16 35 -28 Originality -04 -19 -06 06 39 -40

Similoriries Fluency -21 -33 -03 16 36 -22 Originality -39 -40 -03 I5 41 -18

EPQ variables Psychoticism -03 lb -25 13 26 -27 Extraversion -01 -13 01 I2 16 -06 Neuroticism -24 05 26 -32 -18 OS Lie scale 33 17 -04 I1 -II 45

sex 36 I6 38 IO -36 31 Age -08 03 17 36 40 I7

All values are multiplied by 100. Critical values for a one-tailed test at 5% and 1% levels, respectively, are 0.30 and 0.41.

RESULTS

Preliminary analysis of the results showed that 19 of the 30 Ss in the experiment obtained one or zero errors in the single-channel (Focussed Attention) task and that scores on the task were not related to any of the personality or creativity variables. The word pairs of high and low associative strength were not different from one another with respect either to overall mean scores or patterns of correlations with other variables. The two categories of words were therefore combined in calculating the correlations in Table 1. Owing to appreciable positive skew in the distributions of the four creativity measures, the Errors and Intrusions measures in the Focussed Attention condition, and the Intrusions measure in the Divided Attention condition, logarithmic trans- formations of these data were carried out before the correlations were calculated. Correlations with age and a biserial correlation with sex (M = 1, F = 2) are also given in Table 1.

The following are the major features of Table 1. First, to the extent that the creativity measures are associated with performance on the shadowing task under the ‘Focussed Attention’ condition, the correlations are negative, and are therefore in the direction opposite to the results obtained by Dykes and McGhie (1976). Under the ‘Divided Attention’ condition, the correlations with the Intrusions measures, and to a lesser extent with the Recognition measures, are in the expected direction. Secondly, none of the correlations with the P scale are significant, although there is a ‘marginally significant’ (P < 0.10) tendency for high scoring Ss to make more Intrusions and fewer Recognition errors in the Divided Attention task. Finally, a number of other correlations are of interest, particularly the tendency for female Ss to show a generally poor performance under the Focussed Attention condition, though significantly fewer intrusions in the Divided Attention condition; and for older Ss to show poor performance under the Divided Attention condition. The Lie scale (L) is positively correlated with Recognition errors in the Divided Attention condition, and with overall Errors in the Focussed Attention condition. Neuroticism is negatively correlated with Errors in the Divided Attention task.

The importance of sex and age in accounting for the correlations was further investigated by partialling out these variables independently and conjointly. The biserial correlation with sex was negative for P (r = -0.40, P = 0.015) and negative but non-significant for creativity. Age was negatively correlated with P and positively correlated with the creativity measures, but none of these correlations were significant. Therefore, when partial correlations between creativity and shadowing performance were calculated, most of the relevant correlations were reduced, but retained statistical significance: there was still a clear tendency for performance on the Similarities subtest to be associated with low numbers of Errors and Intrusions on the Focussed Attention task, and for performance on both Kogan-Wallach subtests to be associated with large numbers of Intrusions on the Divided Attention task. When age was separately partialled out, the correlation between P and Divided Attention Intrusions increased to a significant level (r = 0.38, P = 0.02).

Correlations between personality and creativity were also calculated. Contrary to the earlier study of Woody and Claridge (1977), none of the correlations between P and creativity measures approached statistical significance.

740 DAVID RAWLINGS

DISCUSSION

The results provided very tenuous support for the hypothesis that P would be positively correlated with shadowing errors. None of the correlations between P and shadowing measures were significant, although the personality scale was correlated with Divided Attention Intrusions when the effects of age were partialled out. It is possible to find some indirect support for the hypothesis in the finding that males and creative Ss made more Intrusions and fewer Recognition errors in the Divided Attention task: previous studies have found males and creative individuals to be high on P. However, this indirect support is counterbalanced by the fact that under the Focussed Attention condition results tend to be the reverse of those in the Divided Attention condition. Males, low L scale scorers, and Ss scoring high on the Similarities subtest all performed well in the Focussed Attention task. The results raise a number of issues.

(1) First, the failure to obtain a positive correlation between P and creativity measures was contrary to the earlier study of Woody and Claridge (1977). Although our study replicated the untimed conditions employed by the earlier writers, the smaller experimental room and the presence of laboratory equipment may have provided an environment which was less relaxed than that provided by Woody and Claridge. The sample in the present study was also rather smaller. Nevertheless, our failure to approach the very high correlations obtained in the earlier study clearly points to a need for further research into the precise conditions necessary to produce the relationship.

(2) In the present experiment, Ss scoring high on the Similarities subtest performed better than average on the dichotic shadowing task. This is the reverse of the pattern obtained by Dykes and McGhie (1976). A possible explanation for the discrepancy is that creative Ss in the earlier study ‘instructed themselves’ to attend to the non-shadowed ear, and hence obtained results comparable to our results on the Divided Attention Task. In the present study, there was no mention of a recognition task of any kind until after the condition 1 task was completed. Dykes and McGhie do not specify whether Ss were told about an ensuing recognition task, or whether they use one as part of their practice session. We do know that they used two shadowing procedures (words and prose) which were given in reverse order to half the Ss, and which each required a recognition task. So at least half the Ss must have known that a recognition task was going to be required at the completion of the shadowing sessions involving word-pairs, a circumstance which may have provided them with greater motivation to attend to the non-shadowed ear.

(3) The performance of schizophrenics (and creative Ss) on tasks like dichotic shadowing is attributed by writers such as Dykes and McGhie (1976) and Wishner and Wahl (1974) to a defective ‘filter’ mechanism which produces a widening of selective attention and an inability to inhibit irrelevant stimuli. While it is possible to interpret the present experiment within that framework, the very different pattern of results obtained in the Focussed and Divided Attention conditions suggests a quite different explanation. It is plausible that Ss scoring high on measures of creativity are willing to follow the instructions of the experimenter without concern for the consequences of so doing. Thus, in the Focussed Attention task they do concentrate on one ear, as instructed, leading to superior performance. In the Divided Attention task, their performance is greatly disrupted because they obey the experimenter’s (very difficult) command to attend to the secondary as well as the primary channel. They are willing to cooperate with the experimenter to the point of appearing foolish or inadequate. It may be observed that certain aspects of the Lie scale data are substantially the reverse of the creativity data. Specifically, high L scorers manifest more shadowing errors in the Focussed condition, and more recognition errors in the Divided condition. The type of unconcern described in the above explanation may well be reflected in a tendency to ignore considerations of social desirability. This view is strengthened if the specific correlations of creativity measures and Lie scale measures are observed: three of the four correlations attain statistical significance. It is argued, in other words, that a particular response style involving an impulsive disregard for consequences may underlie the pattern of results in Table 1.

(4) Given the interpretation of Table 1 in terms of ‘impulsivity’, it is tempting to relate our data to previous studies involving the impulsivity construct. Specifically, it has been argued that the P scale of the EPQ is related both to questionnaire (Eysenck and Eysenck, 1978) and behavioural

Psychoticism, creativity and dichotic shadowing 741

(Rawlings, 1984) measures of impulsivity. Direct support for this relationship is produced by the current study only with respect to the partial correlation involving P and Divided Attention Intrusions, controlling for age. However, indirect support is obtained from the several correlations involving measures which are characteristically correlated with P. Thus, the significant correlations involving creativity (positively correlated with age in the study of Woody and Claridge, 1977), sex and L scale (Males and low L scorers are consistently higher on P) are all in the direction predicted by an ‘impulsivity’ explanation of the data in Table 1.

If the relationship between P and dichotic shadowing depends largely on evidence which is indirect, it does provide the basis for an interpretation of a number of other studies in which high P scorers have performed in a manner directly the reverse of what might be expected by observation of actual psychotic behaviour. Three important examples of the ‘reversal’ effect will be noted. The finding that high P Ss have fast reaction times, although schizophrenics typically have slow reactions, has already been referred to. The study of Woody and Claridge (1977) in which high P Ss showed highly original performance on creativity tests is apparently inconsistent with the findings of Hebeison (1960), Soueif and Farag (1971) and Kidner (1978), who each found significantly depressed performance by schizophrenics on tests of creative thinking. High P Ss typically show low L scale scores; schizophrenics have high L scale scores (Eysenck and Eysenck, 1976). Findings such as these are sometimes ascribed to drugs, to hospitalization, or to other ‘secondary’ effects of the psychiatric breakdown. This type of explanation is unsatisfactory because it does not explain why the high P Ss actually behave the opposite to expectation, and does not specify the conditions under which such a reversal is likely to occur.

Impulse is defined as “the sudden tendency to act without reflection” (Concise Oxford Dictionary). It is possible to consider the high P scorer as acting quickly, or ‘impulsively’, in order to avoid the need to reflect. This should not be seen as a conscious or deliberate process. Rather, the high P scorer has adopted a behavioural strategy based on previously aversive consequences. The view that the schizophrenic finds decision-making painful, or at the very least difficult, is supported by studies showing that schizophrenic performance deteriorates with increasing levels of response uncertainty (e.g. Marshall, 1973; Hemsley, 1976). It is here argued that high P scorers have similar difficulty in decision-making situations (cf. Rawlings, 1985), but unlike schizophrenics, have sufficient control over their cognitive processes to minimize their losses by adopting highly risky, impulsive behavioural strategies. This style of responding is then reflected in the high P S’s rapid responding on latency tasks irrespective of the need for accuracy; and in his apparent disregard of consequences or of social constraints in performing creativity tests or L scales. As previously argued, the attitude of unconcern which apparently motivates the low L scale scorer may well predispose the same person to obey experimental instructions in a task like dichotic shadowing.

The interpretation outlined above is not dependent, however, on the results of the present experiment. It provides a framework for the explanation of several anomalous results which throw doubt on the validity of P. It may also provide some explanation for why the questions on the P scale do not always have high face validity as predictors of the more ‘passive’ forms of psychosis (cf. Claridge, 1981): a person predisposed to become schizophrenic may be ‘like schizophrenics’ in some ways, but quite the reverse in others. It is also consistent with the view of Eysenck and Eysenck (1976) that the classic psychoses are part of the same cluster of behavioural disturbances as psychopathy and the personality disorders, since these latter disorders frequently display the forms of impulsive and uncaring behaviour under consideration,

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