- Email: [email protected]
Personal tempo, personality, cognitive speed and cognitive performance
336
NOTES AND SHORTER COMMUNICATIONS
Examination of the topography of the response shows that the shortest latencies were found over the post central regions and the longest at the occipital recording sites. The amplitudes show the reverse. They are highest for the centrally recorded potentials and lowest for the occipital recordings. Correlations between the sensation thresholds and the NI at the lower stimulus intensity, as well as the difference of the NI between the two stimulus intensities lay between 0.53 and 0.70 and were significant at the <0.001 level. For the PI and N2 these correlations were significant at the <0.01 level with values between 0.51 and 0.60. The following indicators of pain sensititity were used: 'Pain threshold', 'pain tolerance' and the difference between these two known as the 'pain width'. We found negative correlations between latencies and tolerance values, which were more apparent at the higher stimulus intensity and greatest for the N1, ranging from 0.45 to 0.58 with significance ranging from <0.05 to <0.01. For the PI and N2 correlations were found at the higher stimulus intensity of 0.38 to 0.56, significant at the <0.05 level. The AI correlates negatively with pain tolerance ( - 0 . 3 9 to -0.57, significance <0.05). This means that the SEPs of subjects who are relatively resistant to painful stimuli have shorter component latencies and smaller amplitudes. Subjects with low pain tolerance have very clear and distinctive SEPs. Although no correlations were found between pain threshold and SEPs, pain width was more highly correlated with latencies than was pain tolerance (0.55 to 0.60, significance <0.01). The correlation diminishes for the later components (PI: r = 0.41 to 0.53 and for N2 r = 0.39 to 0.50, significance <0.05 to <0.01). Values on the Anxiety Scale are positively correlated with peak latencies at both stimulus intensities; for the lower intensity (r = 0.49 to 0.57, significance <0.01) and for the higher intensity (r = 0.38 to 0.48, significance <0.05). There were positive correlations between Neuroticism scores and latencies of SEPs. These were greatest for the PI, N2 differences between the two stimulus intensities (r = 0.54 to 0.73), significance <0.001), and for the relationship between Neuroticism and N1 the correlations were 0.41 to 0.48. We found positive correlations between the values on the "Bfs" and latencies, which were highest with P1 (r = 0.47 to 0.55, significance <0.01) and lower with NI and N2 (r = 0.39 to 0.54, significance <0.05) and also with A2 (r = 0.40 to 0.45, significance <0.05). Further positive correlations were found between learning effect and latencies of P1 and N2 lying between 0.50 and 0.62 for P1 and between 0.39 and 0.54 for N2. Correlations between learning effect and A1 at the lower stimulus intensity ranged from 0.42 to 0.64 and between learning effect and A2 were smaller (r = 0.42 to 0.57, significance <0.05). N o correlations were found between extraversion-introversion and physiological parameters. REFERENCES
EYSENCK H. J. and EYSENCK S. B. G. (1964) Manual of the Eysenck Personality Inventory. Univ. of London Press, London; Educational and Industrial Testing Service, San Diego (R. R. Knapp). KL£BELSBERG D. V. (1960) Wiener Determinationsger~t. Dicu3nostica 4, WOLPE J. and LArgO P. J. A. (1962) A fear survey schedule for use in behaviour therapy. Behav. Res. Ther. 2, 27-30. ZERSSEN D. V., KOELLER D. M. and REY E. R. (1970) Die Befindlichkeitsskala (B-S)---Ein einfaches Instrument zur Objektiviering yon Befindlichkeitsst/Srungen, insbesondere im Rahmen von L~ingsschnittuntersuchungen. ArzneimitteI-Forsch. 20, 915-918.
0191-8869/81/040336-02 $02.00/0 Copyright g3 1981 Pergamon Press Ltd
Person. indirid. Di~ Vol. 2, pp. 336 to 338. 1981 Printed in Great Britain. All rights reserved
Personal t e m p o , personality, cognitive speed and cognitive performance
Y. RIM Faculty of Industrial Engineering & Management, Teehnion--lsrael Institute of Technology, Haifa, Israel (Received 16 December 1980) Summary---One hundred young males filled in an untimed personality questionnaire. The time needed was taken to be the subjects' personal tempo. They also worked twice on a timed substitution test; their score on this test was taken to be their cognitive speed. It was hypothesized that personal tempo was related to personality and cognitive speed to performance on cognitive tests. The results confirmed the hypothesis. Those whose personal tempo was faster had higher Extraversion and lower Neuroticism and Lie-scores. Those whose cognitive speed was faster, however, did better on four out of five cognitive tests and had a higher Lie-score. It seems that the two speed factors, as hypothesized by Spearman, are indeed two separate and distinct factors, each correlated with different variables: cognitive and personality. Spearman (1927) differentiated experimentally between two types of speed factors that enter into performance on timed tests or enter into the total amount of time needed to complete an untimed test. One speed factor,
337
NOTES A N D S H O R T E R C O M M U N I C A T I O N S
which might be called cognitive speed, is intrinsic to g; it involves the speed of mental operations. The other form of speed was likened by Spearman to a general attitude or preference for speed in performing any task; it might be called personal tempo. It can be experimentally distinguished from cognitive speed by m e a n s of test items which are within everyone's capability of performing correctly and in which the only source of individual differences is the time required. It has been claimed (Klineberg, 1928) that a timed test t a n penalize persons with a slower personal tempo, e.g. blacks and persons of low socioeconomic status. In summarizing the evidence of results of investigations aimed at elucidating this question, Jensen 0980) concludes: "that the condition of timed versus untimed t e s t s . . , of mental ability is a negligible factor in the observed m e a n differences in the test scores between majority and minority groups" (p. 613). The present study compares the performance on cognitive tests between subjects of high or low personal tempo and cognitive speed. It was hypothesized that cognitive speed would be mainly related to performance on cognitive tests whereas personal tempo would be mainly related to personality. METHOD
Subjects One hundred male candidates for admission to an institute of technology. Mean age: 23 (Range 21-26).
hlstruments used I. Dominoes (Vernon, 195 I): a nonverbal intelligence test with a high g-loading of 0.81. 2. Miltha Intelligence Group Test (Orthar and Morieli, 1966): a verbal intelligence test consisting of five sub-tests.
3. Spatial Perception: a Minnesota-type test measuring the ability to visualize the assembly of two-dimensional shapes into a whole design. 4. Substitution: n u m b e r s are substituted for letters. The test is timed and administered twice, before and after work on a different test. Substitution is done for 3 minutes before and after a 20-minute test. 5. Bennett: a Bennett-type test of mechanical comprehension. 6. Number Series: a test in which one number has to be added to a series of numbers. 7. Eysenck Personality Questionnaire (Eysenck and Eysenck, 1978): measuring Extraversion, Neuroticism, Psychoticism and a 'Lie'-scale. Procedure Subjects were tested in groups of 6-10. They all started simultaneously by filling in the EPI. Of course they worked according to their personal tempo and the questionnaires were unobtrusively arranged according to the order in which they were finished. This enabled the results of all other tests to be tabulated in the order in which the EPI was handed in. The proper timed testing started after the last subject handed in his EPI. RESULTS AND DISCUSSION Table 1 shows that subjects who worked faster in answering the EPI (the first three to five, according to size of group) had significantly lower scores on Neuroticism and the 'Lie'-scale and higher scores on Extraversion. They were significantly higher on two of the five cognitive tests: Dominoes and N u m b e r Series. Table 1. Mean scores on cognitive tests according to personal tempo Personal tempo
Minnesota
Bennett
Number Series
Miltha
Domino
N
E
P
L
41.1 43.6 NS
8.9 9.6 NS
8.4 6.7 0.05
49.9 50.9 NS
35.6 30.7 0.05
6.4 8.3 0.05
14.5 12.9 0.05
3.1 3.4 NS
9.7 I 1.0 NS
Fast Slow Significance NS, not significant.
Table 2. Mean scores on cognitive tests according to cognitive speed
Substitution
Minnesota
Bennett
Number Series
Miltha
Domino
N
F
P
L
High Low Significance
47.4 42.4 0.05
12.7 10.9 0.05
9.1 6.9 0.05
54.5 49.6 0.05
33.8 32.9 NS
5.7 5.6 NS
13.3 13.8 NS
3.2 3. I NS
12.8 10.9 0.05
NS, not significant. Table 2 shows that subjects above the median on the first substitution score had significantly higher scores on four out of the five cognitive tests and had only significantly higher Lie-scores, but were not different on N, E and P from those scoring below the median of the Substitution Test. It may be of interest to add that analysis of the data of the second substitution performance showed only one significant difference: 9.0 for those above the median, vs 7.1 for those below the median (significant at 0.05 level) on the N u m b e r Series Test. Analysis of the data taking both substitution performances into account, shows significant differences on
338
NOTES AND SHORTERCOMMUNICATIONS
Bennett, Number Series and Miltha. In addition, high performers are also higher on Extraversion and the Lie-scale. An analysis of the difference score between the first and second substitution test shows two significant differences only: subjects with large difference scores (i.e. second time higher scores) are higher on Number Series (9.3 vs 6.8) and Psychoticism (3.8 vs 2.7). The results seem to uphold our hypothesis that personal tempo, as expressed by the time taken to fill in an untimed personality questionnaire is related to personality, rather than to cognitive performance. Those with a faster tempo were lower in N and L and higher on E. In addition they were also better on two of the five cognitive tests. Cognitive speed, however, as expressed by the number of letter-number substitutions on a timed test, was found to be related mainly to performance in other cognitive tests (four out of five) and only slightly to personality: one out of four scores. It should be underlined that those of high personal tempo had lower Lie-scores, whereas those of high cognitive speed had higher Lie-scores. REFERENCES EYSENCK H. J. and EYSENCK S. B. G. (1978) Manual of the Eysenck Personality Questionnaire. Hodder & Stoughton, London. JENSEN A. R. (1980) Bias in Mental Testin#. Methuen, London. KLINEBERG O. (1928) An experimental study of speed and other factors in 'racial' differences. Archs Psychol. 93. SPEARMANC. (1927) The Abilities of Man. Macmillan, New York. VERNON P. E. (1951) The Structure of Human Abilities. Methuen, London.
Person.indit'id.Diff.Vol.2. pp. 338 to 340. 1981 Printed in Great Britain.All rightsreserved
0191-8869/8I,~40338~3$02.00/0 Copyright ~) 1981 PergamonPressLtd
A new approach to Eysenck's theory of criminality* BARRY J. McGuRK and CYNTHIA McDOUGALL Psychology Unit, H.M. Remand Centre, Low Newton, Brasside, Durham, DHI 5YV, England
(Received 12 February 1981) Summary--Studies examining Eysenck's theory of criminality by contrasting delinquent and non-delinquent groups have produced equivocal results. Some studies have shown criminals to score higher, as the theory predicts, on psychoticism, neuroticism and extraversion, whilst other studies have not. The current study examines the theory from a new approach by using cluster analysis to demonstrate the heterogeneity of personality types in a delinquent sample (N = 1130) and in a comparison group (N = 100). Four personality types were found in each group. Two personality types which were present in the delinquent sample were not found in the comparison group. The first type consisted of individuals scoring high on neuroticism and extraversion whilst the second type consisted of individuals scoring high on psychoticism, neuroticism and extraversion. These types appeared to be consistent with Eysenck's theory of criminality. INTRODUCTION Eysenck's theory of criminality, first put forward in Crime and Personality (Eysenck, 1964) has received a great deal of attention, but to date research investigations have produced conflicting results. Briefly, the theory is based on the assumption that innate biological factors to some extent determine whether an individual behaves criminally. According to the theory, extraverted people condition less well than introverted people and are consequently less well socialized. In addition, high degrees of neuroticism strongly reinforce the extraverted tendencies favouring antisocial conduct. It is deduced therefore that antisocial conduct, particularly crime, will be found more often in people who score highly on extraversion and neuroticism. It is also suggested that criminals will register higher scores on a third personality dimension, 'psychoticism' (Eysenck, 1970). Support for the theory was found by Wilson and MacLean (1974) who showed that prisoners scored higher on psychoticism, extraversion and neuroticism scales than a comparison group of bus drivers. Eysenck (1974) also found higher levels of psychoticism, extraversion and neuroticism in a group of male prisoners when compared with a control group. Hoghughi and Forrest (1970), however, showed that although approved school boys were significantly more neurotic than normative samples, they were significantly more introverted. Similarly Cochrane (1974) found higher neuroticism scores among delinquents than non-delinquents but not higher extraversion scores. Eysenck and Eysenck have acknowledged that, in the literature, scores on extraversion "sometimes do and sometimes do not separate prisoners and controls in the predicted direction" (1973, p. 693). A major difficulty in investigating Eysenck's theory is that it is very general in application. It proposes that criminals will score high on psyehoticism, extraversion and neuroticism but does not take into account the * The opinions expressed in this paper are the authors and do not necessarily represent those of the Home Office, Prison Department.
NOTES AND SHORTER COMMUNICATIONS
Examination of the topography of the response shows that the shortest latencies were found over the post central regions and the longest at the occipital recording sites. The amplitudes show the reverse. They are highest for the centrally recorded potentials and lowest for the occipital recordings. Correlations between the sensation thresholds and the NI at the lower stimulus intensity, as well as the difference of the NI between the two stimulus intensities lay between 0.53 and 0.70 and were significant at the <0.001 level. For the PI and N2 these correlations were significant at the <0.01 level with values between 0.51 and 0.60. The following indicators of pain sensititity were used: 'Pain threshold', 'pain tolerance' and the difference between these two known as the 'pain width'. We found negative correlations between latencies and tolerance values, which were more apparent at the higher stimulus intensity and greatest for the N1, ranging from 0.45 to 0.58 with significance ranging from <0.05 to <0.01. For the PI and N2 correlations were found at the higher stimulus intensity of 0.38 to 0.56, significant at the <0.05 level. The AI correlates negatively with pain tolerance ( - 0 . 3 9 to -0.57, significance <0.05). This means that the SEPs of subjects who are relatively resistant to painful stimuli have shorter component latencies and smaller amplitudes. Subjects with low pain tolerance have very clear and distinctive SEPs. Although no correlations were found between pain threshold and SEPs, pain width was more highly correlated with latencies than was pain tolerance (0.55 to 0.60, significance <0.01). The correlation diminishes for the later components (PI: r = 0.41 to 0.53 and for N2 r = 0.39 to 0.50, significance <0.05 to <0.01). Values on the Anxiety Scale are positively correlated with peak latencies at both stimulus intensities; for the lower intensity (r = 0.49 to 0.57, significance <0.01) and for the higher intensity (r = 0.38 to 0.48, significance <0.05). There were positive correlations between Neuroticism scores and latencies of SEPs. These were greatest for the PI, N2 differences between the two stimulus intensities (r = 0.54 to 0.73), significance <0.001), and for the relationship between Neuroticism and N1 the correlations were 0.41 to 0.48. We found positive correlations between the values on the "Bfs" and latencies, which were highest with P1 (r = 0.47 to 0.55, significance <0.01) and lower with NI and N2 (r = 0.39 to 0.54, significance <0.05) and also with A2 (r = 0.40 to 0.45, significance <0.05). Further positive correlations were found between learning effect and latencies of P1 and N2 lying between 0.50 and 0.62 for P1 and between 0.39 and 0.54 for N2. Correlations between learning effect and A1 at the lower stimulus intensity ranged from 0.42 to 0.64 and between learning effect and A2 were smaller (r = 0.42 to 0.57, significance <0.05). N o correlations were found between extraversion-introversion and physiological parameters. REFERENCES
EYSENCK H. J. and EYSENCK S. B. G. (1964) Manual of the Eysenck Personality Inventory. Univ. of London Press, London; Educational and Industrial Testing Service, San Diego (R. R. Knapp). KL£BELSBERG D. V. (1960) Wiener Determinationsger~t. Dicu3nostica 4, WOLPE J. and LArgO P. J. A. (1962) A fear survey schedule for use in behaviour therapy. Behav. Res. Ther. 2, 27-30. ZERSSEN D. V., KOELLER D. M. and REY E. R. (1970) Die Befindlichkeitsskala (B-S)---Ein einfaches Instrument zur Objektiviering yon Befindlichkeitsst/Srungen, insbesondere im Rahmen von L~ingsschnittuntersuchungen. ArzneimitteI-Forsch. 20, 915-918.
0191-8869/81/040336-02 $02.00/0 Copyright g3 1981 Pergamon Press Ltd
Person. indirid. Di~ Vol. 2, pp. 336 to 338. 1981 Printed in Great Britain. All rights reserved
Personal t e m p o , personality, cognitive speed and cognitive performance
Y. RIM Faculty of Industrial Engineering & Management, Teehnion--lsrael Institute of Technology, Haifa, Israel (Received 16 December 1980) Summary---One hundred young males filled in an untimed personality questionnaire. The time needed was taken to be the subjects' personal tempo. They also worked twice on a timed substitution test; their score on this test was taken to be their cognitive speed. It was hypothesized that personal tempo was related to personality and cognitive speed to performance on cognitive tests. The results confirmed the hypothesis. Those whose personal tempo was faster had higher Extraversion and lower Neuroticism and Lie-scores. Those whose cognitive speed was faster, however, did better on four out of five cognitive tests and had a higher Lie-score. It seems that the two speed factors, as hypothesized by Spearman, are indeed two separate and distinct factors, each correlated with different variables: cognitive and personality. Spearman (1927) differentiated experimentally between two types of speed factors that enter into performance on timed tests or enter into the total amount of time needed to complete an untimed test. One speed factor,
337
NOTES A N D S H O R T E R C O M M U N I C A T I O N S
which might be called cognitive speed, is intrinsic to g; it involves the speed of mental operations. The other form of speed was likened by Spearman to a general attitude or preference for speed in performing any task; it might be called personal tempo. It can be experimentally distinguished from cognitive speed by m e a n s of test items which are within everyone's capability of performing correctly and in which the only source of individual differences is the time required. It has been claimed (Klineberg, 1928) that a timed test t a n penalize persons with a slower personal tempo, e.g. blacks and persons of low socioeconomic status. In summarizing the evidence of results of investigations aimed at elucidating this question, Jensen 0980) concludes: "that the condition of timed versus untimed t e s t s . . , of mental ability is a negligible factor in the observed m e a n differences in the test scores between majority and minority groups" (p. 613). The present study compares the performance on cognitive tests between subjects of high or low personal tempo and cognitive speed. It was hypothesized that cognitive speed would be mainly related to performance on cognitive tests whereas personal tempo would be mainly related to personality. METHOD
Subjects One hundred male candidates for admission to an institute of technology. Mean age: 23 (Range 21-26).
hlstruments used I. Dominoes (Vernon, 195 I): a nonverbal intelligence test with a high g-loading of 0.81. 2. Miltha Intelligence Group Test (Orthar and Morieli, 1966): a verbal intelligence test consisting of five sub-tests.
3. Spatial Perception: a Minnesota-type test measuring the ability to visualize the assembly of two-dimensional shapes into a whole design. 4. Substitution: n u m b e r s are substituted for letters. The test is timed and administered twice, before and after work on a different test. Substitution is done for 3 minutes before and after a 20-minute test. 5. Bennett: a Bennett-type test of mechanical comprehension. 6. Number Series: a test in which one number has to be added to a series of numbers. 7. Eysenck Personality Questionnaire (Eysenck and Eysenck, 1978): measuring Extraversion, Neuroticism, Psychoticism and a 'Lie'-scale. Procedure Subjects were tested in groups of 6-10. They all started simultaneously by filling in the EPI. Of course they worked according to their personal tempo and the questionnaires were unobtrusively arranged according to the order in which they were finished. This enabled the results of all other tests to be tabulated in the order in which the EPI was handed in. The proper timed testing started after the last subject handed in his EPI. RESULTS AND DISCUSSION Table 1 shows that subjects who worked faster in answering the EPI (the first three to five, according to size of group) had significantly lower scores on Neuroticism and the 'Lie'-scale and higher scores on Extraversion. They were significantly higher on two of the five cognitive tests: Dominoes and N u m b e r Series. Table 1. Mean scores on cognitive tests according to personal tempo Personal tempo
Minnesota
Bennett
Number Series
Miltha
Domino
N
E
P
L
41.1 43.6 NS
8.9 9.6 NS
8.4 6.7 0.05
49.9 50.9 NS
35.6 30.7 0.05
6.4 8.3 0.05
14.5 12.9 0.05
3.1 3.4 NS
9.7 I 1.0 NS
Fast Slow Significance NS, not significant.
Table 2. Mean scores on cognitive tests according to cognitive speed
Substitution
Minnesota
Bennett
Number Series
Miltha
Domino
N
F
P
L
High Low Significance
47.4 42.4 0.05
12.7 10.9 0.05
9.1 6.9 0.05
54.5 49.6 0.05
33.8 32.9 NS
5.7 5.6 NS
13.3 13.8 NS
3.2 3. I NS
12.8 10.9 0.05
NS, not significant. Table 2 shows that subjects above the median on the first substitution score had significantly higher scores on four out of the five cognitive tests and had only significantly higher Lie-scores, but were not different on N, E and P from those scoring below the median of the Substitution Test. It may be of interest to add that analysis of the data of the second substitution performance showed only one significant difference: 9.0 for those above the median, vs 7.1 for those below the median (significant at 0.05 level) on the N u m b e r Series Test. Analysis of the data taking both substitution performances into account, shows significant differences on
338
NOTES AND SHORTERCOMMUNICATIONS
Bennett, Number Series and Miltha. In addition, high performers are also higher on Extraversion and the Lie-scale. An analysis of the difference score between the first and second substitution test shows two significant differences only: subjects with large difference scores (i.e. second time higher scores) are higher on Number Series (9.3 vs 6.8) and Psychoticism (3.8 vs 2.7). The results seem to uphold our hypothesis that personal tempo, as expressed by the time taken to fill in an untimed personality questionnaire is related to personality, rather than to cognitive performance. Those with a faster tempo were lower in N and L and higher on E. In addition they were also better on two of the five cognitive tests. Cognitive speed, however, as expressed by the number of letter-number substitutions on a timed test, was found to be related mainly to performance in other cognitive tests (four out of five) and only slightly to personality: one out of four scores. It should be underlined that those of high personal tempo had lower Lie-scores, whereas those of high cognitive speed had higher Lie-scores. REFERENCES EYSENCK H. J. and EYSENCK S. B. G. (1978) Manual of the Eysenck Personality Questionnaire. Hodder & Stoughton, London. JENSEN A. R. (1980) Bias in Mental Testin#. Methuen, London. KLINEBERG O. (1928) An experimental study of speed and other factors in 'racial' differences. Archs Psychol. 93. SPEARMANC. (1927) The Abilities of Man. Macmillan, New York. VERNON P. E. (1951) The Structure of Human Abilities. Methuen, London.
Person.indit'id.Diff.Vol.2. pp. 338 to 340. 1981 Printed in Great Britain.All rightsreserved
0191-8869/8I,~40338~3$02.00/0 Copyright ~) 1981 PergamonPressLtd
A new approach to Eysenck's theory of criminality* BARRY J. McGuRK and CYNTHIA McDOUGALL Psychology Unit, H.M. Remand Centre, Low Newton, Brasside, Durham, DHI 5YV, England
(Received 12 February 1981) Summary--Studies examining Eysenck's theory of criminality by contrasting delinquent and non-delinquent groups have produced equivocal results. Some studies have shown criminals to score higher, as the theory predicts, on psychoticism, neuroticism and extraversion, whilst other studies have not. The current study examines the theory from a new approach by using cluster analysis to demonstrate the heterogeneity of personality types in a delinquent sample (N = 1130) and in a comparison group (N = 100). Four personality types were found in each group. Two personality types which were present in the delinquent sample were not found in the comparison group. The first type consisted of individuals scoring high on neuroticism and extraversion whilst the second type consisted of individuals scoring high on psychoticism, neuroticism and extraversion. These types appeared to be consistent with Eysenck's theory of criminality. INTRODUCTION Eysenck's theory of criminality, first put forward in Crime and Personality (Eysenck, 1964) has received a great deal of attention, but to date research investigations have produced conflicting results. Briefly, the theory is based on the assumption that innate biological factors to some extent determine whether an individual behaves criminally. According to the theory, extraverted people condition less well than introverted people and are consequently less well socialized. In addition, high degrees of neuroticism strongly reinforce the extraverted tendencies favouring antisocial conduct. It is deduced therefore that antisocial conduct, particularly crime, will be found more often in people who score highly on extraversion and neuroticism. It is also suggested that criminals will register higher scores on a third personality dimension, 'psychoticism' (Eysenck, 1970). Support for the theory was found by Wilson and MacLean (1974) who showed that prisoners scored higher on psychoticism, extraversion and neuroticism scales than a comparison group of bus drivers. Eysenck (1974) also found higher levels of psychoticism, extraversion and neuroticism in a group of male prisoners when compared with a control group. Hoghughi and Forrest (1970), however, showed that although approved school boys were significantly more neurotic than normative samples, they were significantly more introverted. Similarly Cochrane (1974) found higher neuroticism scores among delinquents than non-delinquents but not higher extraversion scores. Eysenck and Eysenck have acknowledged that, in the literature, scores on extraversion "sometimes do and sometimes do not separate prisoners and controls in the predicted direction" (1973, p. 693). A major difficulty in investigating Eysenck's theory is that it is very general in application. It proposes that criminals will score high on psyehoticism, extraversion and neuroticism but does not take into account the * The opinions expressed in this paper are the authors and do not necessarily represent those of the Home Office, Prison Department.