A single strain, NOD/LTJ, appeared strongly to influence the magnitude (and perhaps direction) of the correlations with spontaneous alternation. Removing this strain resulted in lower values for these correlations (all r < 0.19; P > 0.54). The degree of preference for objects was not significantly correlated with any other measure (all r < −0.33; P > 0.26). The number of rears in the initial test of activity in a novel environment was relatively strongly associated with the number of head dips in the hole-board task (r = 0.77), and both measures were highly genetically correlated with locomotor activity.
