An ANOVA with socio-economic level and sex as independent variables and intrasexual competitiveness as the dependent variable showed a highly significant main effect of socio-economic status, F (2,1629) = 17.96, p < .001, partial η 2 = .022, no effect of sex, F (1,1629) = .21, p = .64, partial η 2 = .0001, and a significant interaction between sex and socio-economic status, F (2,1629) = 3.92, p = .02, partial η 2 = .005.
A single ANOVA simultaneously examining the effect of fathers' and mothers' occupational status on the level of intrasexual competitiveness among women showed that neither the occupational status of the mother, F (7,564) = 1.86, p = .073, partial η 2 = .023, nor that of the father, F (7,564) = 1.12, p = .35, partial η 2 = .014, had a significant effect (although the maternal effect was marginally significant), in part due, of course, to the high correlation between the two variables.