As noted by Satz, the prevalence of lateralized
language in the general population is underestimated substantially
by the proportion of people who show the typical asymmetry
on a laterality task. In a series of two dichotic listening
experiments with a total of 171 right-handers and 170 left-handers,
we tested the hypothesis that increased reliability of
measurement will lead to increased classification accuracy.
Experiment 1 showed that neither the frequency nor magnitude
of the right-ear advantage (REA) for fused rhyming words
increased as the number of trials increased from 120 to
480. Ear-difference scores were highly reliable (r
= .85), even when based on 120 trials. Experiment 2, which
involved lists of dichotic word pairs, yielded similar
results. Even though retest reliability of the ear-difference
score for 132 word pairs was only .45, neither the incidence
nor strength of the REA increased significantly when the
number of pairs was increased to 528. The results indicate
that the poor classification accuracy of dichotic listening
tasks cannot be attributed to unreliability. (JINS,
2000, 6, 539–547.)
