Table 2. Stochastic actor-based models of substance use of cigarettes, alcohol, and marijuana and friendship networks with number of friends who smoked/drank/used marijuana effects.
| Effect name | Sunshine High | Jefferson High |
|---|---|---|
| Smoking behavior |
beta (s.e.) |
beta (s.e.) |
| Rate smoking behavior (period 1) | 13.18** (4.86) |
9.14*** (1.57) |
| Rate smoking behavior (period 2) | 21.31*** (3.28) |
13.84*** (3.42) |
| Smoking behavior linear shape | -2.51*** (0.11) |
-2.16*** (0.10) |
| Smoking behavior quadratic shape | 0.73*** (0.04) |
0.70*** (0.06) |
| In-degree | 0.01 (0.01) |
0.01 (0.01) |
| Smoking behavior peer influence | 0.54*** (0.13) |
0.77*** (0.15) |
| Parental support | -0.13 (0.19) |
-0.02 (0.14) |
| Parental monitoring | -0.05 (0.26) |
-0.05 (0.22) |
| Black | -0.33** (0.12) |
- |
| Latino | -0.13* (0.05) |
- |
| Depressive symptoms | 0.07 (0.06) |
0.12* (0.05) |
| Drinking behavior | 0.05† (0.03) |
0.02 (0.06) |
| Number of friends who drank | 0.01 (0.02) |
0.00 (0.01) |
| Marijuana use | 0.22*** (0.06) |
0.14* (0.06) |
| Number of friends who used marijuana | 0.02 (0.05) |
-0.02 (0.03) |
| Drinking behavior |
beta (s.e.) |
beta (s.e.) |
| Rate drinking behavior (period 1) | 15.86*** (1.68) |
9.94*** (0.94) |
| Rate drinking behavior (period 2) | 16.83*** (2.24) |
13.21* (5.68) |
| Drinking behavior linear shape | -1.38*** (0.07) |
-1.01*** (0.11) |
| Drinking behavior quadratic shape | 0.27*** (0.03) |
0.20*** (0.02) |
| In-degree | 0.01 (0.01) |
0.01 (0.01) |
| Drinking behavior peer influence | 0.28** (0.12) |
0.38* (0.16) |
| Parental support | -0.06 (0.06) |
-0.07 (0.06) |
| Parental monitoring | -0.19 (0.20) |
-0.47** (0.17) |
| Black | -0.11* (0.04) |
- |
| Latino | 0.07† (0.04) |
- |
| Depressive symptoms | 0.06* (0.03) |
0.02 (0.03) |
| Smoking behavior | 0.03 (0.06) |
0.01 (0.02) |
| Number of friends who smoked | 0.01 (0.01) |
0.01 (0.01) |
| Marijuana use | 0.20*** (0.05) |
0.15** (0.05) |
| Number of friends who used marijuana | 0.01 (0.02) |
-0.02 (0.01) |
| Marijuana use |
beta (s.e.) |
beta (s.e.) |
| Rate marijuana use (period 1) | 2.68*** (0.50) |
2.42*** (0.34) |
| Rate marijuana use (period 2) | 4.97*** (0.57) |
4.83*** (0.83) |
| Marijuana use linear shape | -2.48*** (0.29) |
-2.14*** (0.32) |
| Marijuana use quadratic shape | 1.13*** (0.13) |
1.06*** (0.09) |
| In-degree | 0.03 (0.05) |
0.02 (0.02) |
| Marijuana use peer influence | 1.43** (0.38) |
1.32*** (0.49) |
| Parental support | -0.03 (0.23) |
0.12 (0.19) |
| Parental monitoring | -0.34 (0.46) |
0.00 (0.46) |
| Black | 0.17 (0.11) |
- |
| Latino | 0.07 (0.09) |
- |
| Depressive symptoms | -0.08 (0.08) |
0.12 (0.12) |
| Smoking behavior | 0.07 (0.11) |
0.05 (0.06) |
| Number of friends who smoked | 0.02 (0.06) |
0.03 (0.05) |
| Drinking behavior | 0.12 (0.08) |
0.06 (0.08) |
| Number of friends who drank | -0.04 (0.04) |
-0.04 (0.04) |
| Friendship network dynamics |
beta (s.e.) |
beta (s.e.) |
| Friendship rate (period 1) | 16.04*** (0.81) |
18.02*** (1.40) |
| Friendship rate (period 2) | 7.75*** (0.78) |
11.75*** (0.93) |
| Out-degree (density) | -4.15*** (0.18) |
-2.14*** (0.40) |
| Reciprocity | 3.11*** (0.16) |
2.57*** (0.11) |
| Transitive triplets | 0.71** (0.22) |
0.62*** (0.05) |
| 3-cycles | -0.29 (0.40) |
-0.42*** (0.12) |
| Out-degree–popularity | -0.32*** (0.08) |
-0.19*** (0.04) |
| In-degree–popularity | -0.05** (0.02) |
-0.06** (0.02) |
| Out-out degree^(1/2) assortativity | -0.07* (0.03) |
-0.12*** (0.02) |
| In-in degree^(1/2) assortativity | 0.48*** (0.08) |
0.37*** (0.07) |
| Race similarity | 1.18*** (0.08) |
- |
| Gender similarity | 0.29*** (0.04) |
0.23*** (0.06) |
| Grade similarity | 0.62*** (0.05) |
0.57*** (0.05) |
| Parental education similarity | 0.09** (0.03) |
0.05 (0.05) |
| Smoking similarity (peer selection) | 0.01 (0.08) |
0.24* (0.10) |
| Drinking similarity (peer selection) | 0.12* (0.05) |
0.13** (0.05) |
| Marijuana use similarity (peer selection) | 0.27*** (0.07) |
0.22* (0.09) |
| Limited nomination ego | -0.84*** (0.25) |
-1.38*** (0.21) |
Notes
† Two-sided p<0.1
* Two-sided p<0.05
** Two-sided p<0.01
*** Two-sided p<0.001