Averages of intelligence and psychosocial functioning across levels of socioeconomic status.

ρ = Spearman's correlation coefficient; ρadj = partial Spearman's, i.e. adjusted for PF/IQ; *** = p<0.001; NMH = Non-manual workers, higher level; NMI = Non-manual workers, intermediate level; NML = Non-manual workers, lower level; SMW = Skilled manual workers; UMW = Unskilled manual workers; a Skewness = −0.191 (p<0.001); b Skewness = −0.073 (p<0.001). Mean and standard deviation (SD) of intelligence (IQ) and psychosocial functioning (PF) across levels of SES indicators;