TABLE 1—
Covariate Distributions for Gang vs Nongang Members, Measured at Ages 10–12 Years, Before and After Propensity Score Matching: Seattle Social Development Project, Washington, 1985–2008
| Before Matching (n = 808) |
After Matching (n = 346) |
|||||
| Variables | % | Mean (SE) | P | % | Mean (SE) | P |
| Demographic characteristics | ||||||
| Male gender | <.01 | .96 | ||||
| Gang | 76 | 76 | ||||
| Nongang | 44 | 74 | ||||
| Race/ethnicity | ||||||
| White | <.01 | .63 | ||||
| Gang | 29 | 29 | ||||
| Nongang | 52 | 33 | ||||
| African American | <.01 | .52 | ||||
| Gang | 42 | 42 | ||||
| Nongang | 21 | 36 | ||||
| Native American | .01 | .73 | ||||
| Gang | 9 | 9 | ||||
| Nongang | 4 | 10 | ||||
| Asian American | .42 | .68 | ||||
| Gang | 20 | 20 | ||||
| Nongang | 23 | 21 | ||||
| Neighborhood factors | ||||||
| Availability of marijuana | <.01 | .86 | ||||
| Gang | 1.99 (0.07) | 1.99 (0.07) | ||||
| Nongang | 1.55 (0.03) | 1.95 (0.08) | ||||
| Neighborhood kids in trouble | <.01 | .77 | ||||
| Gang | 0.52 (0.04) | 0.52 (0.04) | ||||
| Nongang | 0.25 (0.02) | 0.51 (0.04) | ||||
| Low neighborhood attachment | .06 | .74 | ||||
| Gang | 1.88 (0.05) | 1.88 (0.05) | ||||
| Nongang | 1.78 (0.02) | 1.92 (0.06) | ||||
| Family factors | ||||||
| Povertya | <.01 | .89 | ||||
| Gang | 0.32 (0.06) | 0.32 (0.06) | ||||
| Nongang | −0.06 (0.03) | 0.31 (0.07) | ||||
| Family structure | ||||||
| Two biological or adoptive parents | <.01 | .22 | ||||
| Gang | 31 | 31 | ||||
| Nongang | 50 | 33 | ||||
| One biological parent and one stepparent | .54 | .99 | ||||
| Gang | 11 | 11 | ||||
| Nongang | 13 | 10 | ||||
| One parent only | .04 | .94 | ||||
| Gang | 32 | 32 | ||||
| Nongang | 22 | 35 | ||||
| One parent and other adults | <.01 | .72 | ||||
| Gang | 13 | 13 | ||||
| Nongang | 7 | 12 | ||||
| No parents in home | .03 | .59 | ||||
| Gang | 13 | 13 | ||||
| Nongang | 8 | 10 | ||||
| Sibling antisocial behavior | .01 | .38 | ||||
| Gang | 0.14 (0.02) | 0.14 (0.02) | ||||
| Nongang | 0.10 (0.01) | 0.15 (0.02) | ||||
| Poor family management | .06 | .91 | ||||
| Gang | 1.63 (0.04) | 1.63 (0.04) | ||||
| Nongang | 1.56 (0.02) | 1.64 (0.04) | ||||
| Parent proviolent attitudes | <.01 | .84 | ||||
| Gang | 1.25 (0.04) | 1.25 (0.04) | ||||
| Nongang | 1.12 (0.01) | 1.25 (0.04) | ||||
| School factors | ||||||
| Low academic aspirations | <.01 | .9 | ||||
| Gang | 2.08 (0.06) | 2.08 (0.06) | ||||
| Nongang | 1.86 (0.03) | 2.04 (0.07) | ||||
| Low school commitment | <.01 | .77 | ||||
| Gang | 2.48 (0.05) | 2.48 (0.05) | ||||
| Nongang | 2.22 (0.02) | 2.46 (0.05) | ||||
| Low school attachment | .09 | .99 | ||||
| Gang | 2.07 (0.05) | 2.07 (0.05) | ||||
| Nongang | 1.98 (0.02) | 2.08 (0.06) | ||||
| Academic achievementb | <.01 | .88 | ||||
| Gang | 497 (3.6) | 497 (3.6) | ||||
| Nongang | 523 (1.9) | 502 (3.8) | ||||
| Learning disability | <.01 | .6 | ||||
| Gang | 19 | 19 | ||||
| Nongang | 7 | 15 | ||||
| Peer factors | ||||||
| Association with friends who engage in problem behaviors | <.01 | .63 | ||||
| Gang | 1.07 (0.09) | 1.07 (0.09) | ||||
| Nongang | 0.70 (0.04) | 0.97 (0.09) | ||||
| Individual factors | ||||||
| Antisocial beliefs | <.01 | .8 | ||||
| Gang | 1.51 (0.04) | 1.51 (0.04) | ||||
| Nongang | 1.37 (0.02) | 1.51 (0.05) | ||||
| Alcohol use | .07 | .97 | ||||
| Gang | 0.63 (0.06) | 0.63 (0.06) | ||||
| Nongang | 0.53 (0.03) | 0.65 (0.07) | ||||
| Marijuana initiation | <.01 | .75 | ||||
| Gang | 14 | 14 | ||||
| Nongang | 6 | 12 | ||||
| Violent behavior | <.01 | .7 | ||||
| Gang | 1.23 (0.04) | 1.23 (0.04) | ||||
| Nongang | 0.93 (0.02) | 1.18 (0.05) | ||||
| Externalizing behavior | <.01 | .48 | ||||
| Gang | 0.39 (0.03) | 0.39 (0.03) | ||||
| Nongang | 0.20 (0.01) | 0.34 (0.03) | ||||
| Hyperactivity | <.01 | .87 | ||||
| Gang | 0.88 (0.04) | 0.88 (0.04) | ||||
| Nongang | 0.66 (0.02) | 0.83 (0.05) | ||||
| Poor refusal skills | <.01 | .87 | ||||
| Gang | 2.28 (0.07) | 2.28 (0.07) | ||||
| Nongang | 2.09 (0.04) | 2.27 (0.08) | ||||
a
Standardized composite variable.
b
As determined by the California Achievement Test score.