In 1987 a pilot project of 150 individuals who had participated for the first time in the Psychophysical Research Laboratory’s (PRL) Ganzfeld studies (a state of semi-sensory deprivation which facilitates psi abilities) were asked to report on their hand-preference. PRL was located at Princeton Junction, NJ and directed by Mr. Charles (Chuck) Honorton). At that time I was participating as a volunteer participant at the PRL. According to Geschwind (1974), self-report is generally regarded as the best single measure of lateral preference. Participants were requested to return a postcard, giving information on their hand preference as follows: right-handed, left-handed or mixed-handed. There was an 80% return rate for the postcards. A preliminary analysis of the results showed the following:
- R Preference (n=91)
- L Preference (n=11)
- Mixed (n=19)
The handedness estimates were compared with first-place hits on a Ganzfeld psiexperiment. Among the 91 right-handers, only 29 had direct Ganzfeld hits (32%, z=1.38). Of the left-handers, an even smaller proportion had direct hits on the Ganzfeld, 2 out of 11 (18%, z =-.17). However, there were 10 mixed-handed subjects with direct hits, out of 19 (53%, z = 2.2). While this was a preliminary study, the results certainly warrant further investigation.
How are mixed-handers different from strong right- or left-handers? The distribution of mixed-handedness ranges between 24% to 34% in the general population and more males than females are mixed-handed (Annett, 1970). Mixed-handedness may be a normal variant on the right/left continuum (Annett, 1967, 1970, 1972). She demonstrated that the handedness distribution on the general population should be regarded as continuous, rather than a discrete right/left distribution.
Bakan (1975) found a familial influence for ambilaterality: mixed- handers reported far more left-handed and mixed-handed relatives than right-handers did. Most adults with mixed hand preference appear to be cognitively and neurologically normal (Bishop, 1983). The assumption that mixed handedness reflects immature, underdeveloped cerebral lateralization is not confirmed. Mixed-handedness may also be a product of environmental pressures. On the whole, ambilateral adults with mixed-hand preference are cognitively and neurologically normal and may represent a normal, genetic variation. Mixed-handers may have a unique perspective on the world and behave according to their different view.