Table 2.
Parameter Estimates of SIENA for Friend Selection and Sexual Debut
| Model 1
|
Model 2
|
|||
|---|---|---|---|---|
| Est. | SE | Est. | SE | |
| Selection parameters | ||||
| Structural effects | ||||
| Outdegree | −4.716*** | .072 | −4.716*** | .075 |
| Reciprocity | 2.144*** | .038 | 2.145*** | .039 |
| Transitive triplets | 0.482*** | .018 | 0.482*** | .019 |
| Indegree popularity (sqrt) | 0.135*** | .018 | 0.135*** | .018 |
| Outdegree activity (sqrt) | 0.019 | .018 | 0.019 | .018 |
| Similarity effects: choosing alters similar to oneself | ||||
| Sexual intercourse | 0.195*** | .021 | ||
| Male Ego: Sexual Intercourse | 0.044* | .022 | ||
| Female Ego: Sexual Intercourse | 0.158*** | .025 | ||
| Male | 0.223*** | .020 | 0.221*** | .02 |
| Race | 0.679*** | .035 | 0.677*** | .034 |
| Age | 2.436*** | .124 | 2.438*** | .122 |
| Parental education | 0.075*** | .021 | 0.076*** | .022 |
| Religiosity | 0.110*** | .030 | 0.111*** | .034 |
| Binge drinking | 0.234*** | .036 | 0.231*** | .035 |
| GPA | 0.472*** | .056 | 0.471*** | .052 |
| Shared extracurricular activities | 0.194*** | .016 | 0.195*** | .017 |
| Alter effects: who is more often nominated? | ||||
| Sexual intercourse | 0.087*** | .022 | ||
| Male ego: Sexual intercourse | 0.075** | .024 | ||
| Female ego: Sexual intercourse | 0.010 | .026 | ||
| Male | 0.028 | .019 | 0.029 | .022 |
| Age | −0.006 | .012 | −0.006 | .012 |
| Parental education | 0.016 | .022 | 0.016 | .022 |
| Religiosity | −0.009 | .008 | −0.009 | .009 |
| Binge drinking | 0.018 | .016 | 0.016 | .016 |
| GPA | 0.022 | .016 | 0.022 | .015 |
| Ego effects: who nominates more alters? | ||||
| Sexual Intercourse | −0.125*** | .024 | ||
| Male ego: Sexual intercourse | −0.024 | .026 | ||
| Female ego: Sexual intercourse | −0.102*** | .028 | ||
| Male | 0.101*** | .022 | 0.185*** | .034 |
| Age | −0.053*** | .012 | −0.053*** | .012 |
| Parental education | 0.010 | .027 | 0.008 | .023 |
| Religiosity | −0.041*** | .011 | −0.041*** | .011 |
| Binge drinking | 0.041* | .017 | 0.039* | .017 |
| GPA | −0.001 | .015 | −0.001 | .015 |
| Sunshine school | −1.808*** | .118 | −1.821*** | .116 |
| School interactions (Sunshine = 1) | ||||
| Transitive triplets | 0.098*** | .028 | 0.098*** | .030 |
| Outdegree activity (sqrt) | 0.230*** | .032 | 0.232*** | .034 |
| Same race | 1.085*** | .076 | 1.091*** | .073 |
| Age similarity | 0.618** | .218 | 0.617** | .207 |
| Religiosity ego | −0.095*** | .021 | −0.097*** | .020 |
| GPA alter | 0.126*** | .029 | 0.126*** | .027 |
| Rate effects | ||||
| Jefferson, Period 1 | 13.874*** | .527 | 13.855*** | .602 |
| Jefferson, Period 2 | 15.330*** | .721 | 15.348*** | .802 |
| Sunshine, Period 1 | 11.492*** | .552 | 11.490*** | .517 |
| Sunshine, Period 2 | 9.504*** | .494 | 9.501*** | .434 |
| Behavior parameters | ||||
| Debuted peer (total exposure) | 0.334*** | .074 | 0.332*** | .079 |
| Male: Debuted peer (total exposure) | −0.124 | .173 | ||
| Male | −0.068 | .123 | −0.036 | .146 |
| Age | 0.184* | .082 | 0.187** | .067 |
| Religiosity | −0.153** | .057 | −0.154** | .054 |
| Binge drinking | 0.361*** | .092 | 0.363*** | .092 |
| GPA | −0.312** | .101 | −0.313*** | .081 |
| Pubertal development | 0.359* | .146 | 0.362** | .144 |
| Extracurricular activities | 0.049 | .178 | 0.050 | .149 |
| Rates for Jefferson, Period 1 | 0.049*** | .014 | 0.049*** | .015 |
| Rates for Jefferson, Period 2 | 0.348*** | .061 | 0.353*** | .082 |
| Rates for Sunshine, Period 1 | 0.077*** | .018 | 0.078*** | .018 |
| Rates for Sunshine, Period 2 | 0.449*** | .058 | 0.451*** | .074 |
| Overall maximum convergence ratio | 0.230 | 0.248 | ||
Note. Convergence t-ratios for all parameters are below .100. Values are unstandardized contributions to log probabilities. Indegree popularity refers to the extent to which popular students receive more future friendship nominations. Outdegree-activity tests whether adolescents who named more friends were more likely to add more friends at a later point. Interaction terms in this model refer to the product of the gender dummy, sexual debut covariate, and network functions and differ from the traditional regression model’s approach where all relevant combinations of covariates are multiplied. SIENA = Simulation Investigation for Empirical Network Analysis; GPA = grade point average.
p < .05.
p < .01.
p < .001 (two-tailed tests).