highly significantp < 0.0001
An analysis of independent contrasts based on this hypothetical relationship gave a highly significant relationship between WPM and r diff both when within-species variation was ignored ( β = 5.48, t = 6.57, df = 48, p < 0.0001) and included ( β = 6.59, t = 9.12, df = 55, p < 0.0001).