Table 3

Mean personality traits for never, non-current, and current marijuana users.

NEO-PI-R scales

Never-user (n = 576)

Former user (n = 380)

Current user (n = 88)

F

Partial η²

Neuroticism

50.0 (.42)

50.4 (.50)

50.9 (1.01)

0.4

.001

Extraversion

49.0 (.37)

48.5 (.44)

49.4 (.88)

0.7

.001

Openness

45.5 (.37)^a

46.1 (.44)^a

48.8 (.88)^b

5.5**

.011

Agreeableness

51.6 (.40)^a

49.6 (.49)^b

48.4 (.98)^b

6.3**

.012

Conscientiousness

49.7 (.43)^a

47.0 (.51)^b

47.0 (1.03)^b

8.0**

.016

N1: Anxiety

50.5 (.38)

50.8 (.46)

50.6 (.92)

0.1

.000

N2: Angry Hostility

50.0 (.41)^a

51.2 (.50)^ab

53.0 (1.00)^b

3.9*

.008

N3: Depression

50.4 (.47)

51.4 (.57)

51.2 (1.14)

0.7

.001

N4: Self-consciousness

49.2 (.43)

50.0 (.51)

49.1 (1.03)

0.7

.001

N5: Impulsiveness

48.7 (.40)

49.7 (.48)

50.1 (.96)

1.4

.003

N6: Vulnerability

49.6 (.47)^a

51.5 (.57)^b

52.2 (1.15)^b

3.7*

.007

E1: Warmth

49.1 (.43)^a

47.1 (.52)^b

47.1 (1.03)^ab

4.2*

.008

E2: Gregariousness

50.8 (.41)

50.1 (.50)

50.4 (1.00)

0.5

.001

E3: Assertiveness

49.7 (.42)

49.4 (.51)

50.7 (1.03)

0.7

.001

E4: Activity

47.4 (.40)^a

46.9 (.48)^a

50.1 (.97)^b

4.6*

.009

E5: Excitement-Seeking

47.1 (.39)^a

48.5 (.47)^b

49.9 (.94)^b

4.3*

.009

E6: Positive Emotions

49.0 (.42)

47.4 (.51)

48.4 (1.02)

2.3

.005

O1: Fantasy

47.9 (.36)

48.5 (.44)

48.9 (.87)

0.8

.001

O2: Aesthetics

48.5 (.40)^a

49.0 (.48)^a

51.4 (.96)^b

3.9*

.008

O3: Feelings

46.6 (.38)

47.3 (.46)

48.6 (.92)

1.9

.004

O4: Actions

45.2 (.42)^a

45.9 (.50)^a

48.1 (1.01)^b

3.2*

.006

O5: Ideas

47.2 (.40)^a

46.2 (.49)^a

49.7 (.97)^b

5.7**

.011

O6: Values

44.0 (.37)^a

46.1 (.44)^b

46.9 (.89)^b

7.9**

.015

A1: Trust

47.3 (.43)

46.5 (.52)

44.7 (1.04)

2.7

.005

A2: Straightforwardness

51.4 (.41)

50.0 (.49)

49.2 (.99)

2.9

.006

A3: Altruism

51.4 (.42)^a

49.4 (.51)^b

50.4 (1.03)^ab

3.8*

.008

A4: Compliance

50.4 (.45)^a

48.2 (.55)^b

47.2 (1.10)^b

5.4**

.011

A5: Modesty

51.9 (.42)

50.7 (.50)

49.5 (1.01)

2.8

.006

A6: Tender-mindedness

52.5 (.41)

51.6 (.50)

52.2 (.99)

1.0

.002

C1: Competence

50.0 (.47)^a

47.7 (.56)^b

47.1 (1.13)^b

5.0**

.010

C2: Order

47.6 (.39)

46.5 (.48)

45.9 (.95)

2.1

.004

C3: Dutifulness

49.2 (.42)^a

46.2 (.51)^b

46.2 (1.01)^b

9.8**

.019

C4: Achievement Striving

49.0 (.45)^a

46.6 (.55)^b

46.1 (1.09)^b

6.0**

.012

C5: Self-Discipline

48.7 (.46)^a

46.5 (.55)^b

45.6 (1.10)^b

5.3**

.010

C6: Deliberation

53.2 (.44)^a

50.9 (.54)^b

49.9 (1.07)^b

6.6**

.013

Note. Estimated marginal means (Standard Errors), statistical tests, and effect sizes computed after controlling for age, sex, ethnicity (black, white), and education (n = 1013).

Means with different superscripts differ significantly at p < .05.

* p < .05; ** p < .01

Terracciano et al. BMC Psychiatry 2008 8:22   doi:10.1186/1471-244X-8-22