Skip to main content
. Author manuscript; available in PMC: 2013 Oct 22.
Published in final edited form as: Psychol Med. 2007 Apr 20;37(7):947–959. doi: 10.1017/S0033291707009920

Table 3.

Estimates of thresholds on a common scale, means, standard deviations, and the model implied correlations.

Cigarettes
Threshold Age 8-11 Age 12-14 Age 15-17
1 0.00 0.00 0.00
2 1.00 1.00 1.00
3 1.26 1.26 1.26
M 1.91 2.62 3.68
SD 2.33 1.81 1.77
Age 8-11 1.00
Age 12-14 0.86 1.00
Age 15-17 0.67 0.81 1.00
Alcohol
Threshold Age 8-11 Age 12-14 Age 15-17 Age 15-17
1 0.00 0.00 0.00 0.00
2 1.00 1.00 1.00 1.00
3 1.18 1.18 1.18 -
M 0.51 1.32 2.29 2.62
SD 2.05 1.68 1.44 1.33
Age 8-11 1.00
Age 12-14 0.85 1.00
Age 15-17 0.60 0.75 1.00
Age 18-21 0.28 0.45 0.65 1.00
Marijuana
Threshold Age 8-11 Age 12-14 Age 15-17 Age 15-17 Age 18-21
1 0.00 0.00 0.00 0.00 0.00
2 1.00 1.00 1.00 1.00 1.00
3 0.85 0.85 0.85 0.85 0.85
M 4.47 2.53 1.23 0.21 0.13
SD 2.25 1.82 1.76 1.69 1.56
Age 8-11 1.00
Age 12-14 0.79 1.00
Age 15-17 0.61 0.79 1.00
Age 18-21 0.45 0.61 0.77 1.00
Age 22-25 0.39 0.46 0.61 0.78 1.00
Cocaine
Threshold Age 8-11 Age 12-14 Age 15-17 Age 15-17 Age 18-21
1 0.00 0.00 0.00 0.00 0.00
2 - 1.00 1.00 1.00 1.00
3 - - 0.91 0.91 0.91
M −3.94 −1.80 −0.87 0.18 0.49
SD 2.19 1.55 1.80 1.81 1.78
Age 8-11 1.00
Age 12-14 0.81 1.00
Age 15-17 0.64 0.80 1.00
Age 18-21 0.46 0.63 0.80 1.00
Age 22-25 0.41 0.52 0.71 0.83 1.00
Stimulants
Threshold Age 8-11 Age 12-14 Age 15-17 Age 15-17 Age 18-21
1 0.00 0.00 0.00 0.00 0.00
2 1.00 1.00 1.00 1.00 1.00
3 − 0.89 0.89 0.89 0.89
M −3.26 −1.94 −0.65 0.42 0.61
SD 2.18 2.00 1.88 1.75 1.69
Age 8-11 1.00
Age 12-14 0.81 1.00
Age 15-17 0.66 0.84 1.00
Age 18-21 0.51 0.65 0.79 1.00
Age 22-25 0.44 0.57 0.70 0.84 1.00