Table 1.

Means and standard deviations of demographic variables by MAOA genotype

Measure	High activity MAO (n = 419)		Low activity MAO (n = 253)
	M	SD	M	SD
Age	15.7	1.6	15.6	1.7
Family income	49.2	44.4	53.4	59.3
DPA	0.23	0.25	0.20	0.25
Overt ASB	0.34	0.92	0.38	0.94
Covert ASB	0.69	1.47	0.89	1.85

Overt and covert ASB each reflect behavior across three waves of data collection

DPA deviant peer affiliation; ASB antisocial behavior