Left-handers are thought to possess a number of special cognitive abilities. Some of these abilities are good, some bad. Whether or not these differences in cognitive ability exist often goes to the heart of genetic models, which attempt to explain why left handedness exists. We have collected data from a number of sources to examine the relationship between handedness and factors such as cognitive ability and schizotypy. In general we find that left- and mixed-handers do worse overall. We also find that the lower levels of cognitive ability are not related to birth stress, which is one putative cause of left-handedness.
The Flinders Handedness Survey (FLANDERS)
This page contains information related to the FLANDERS. The original article is to be published in Cortex.
Instructions to the participants are given at the top of the questionnaire together with some questions relating to basic demographic data. Responses of ‘left’, ‘either’ and ‘right’ are assigned scores of -1, 0 and +1, respectively. These scores are then summed to give a test score that ranges from -10 to +10. Individuals with scores ranging between -10 and -5 are deemed to be left-handed whereas individuals with scores ranging between +5 and +10 are right-handed. Individuals with scores between these ranges (-4 to +4) are mixed-handed.
Source article: Nicholls, M.E.R., Thomas, N.A., Loetscher, T. & Grimshaw, G. (2013). The Flinders Handedness survey (FLANDERS): A brief measure of skilled hand preference. Cortex.
Printable versions of the FLANDERS in English and other languages:
Chapman, H. L., Grimshaw, G. M., & Nicholls, M. E. R. (in press). Going beyond students: An association between mixed-hand preference and schizotypy subscales in a general population. Psychiatry Research.
Nicholls, M. E. R., Chapman, H .L., Loetscher, T., & Grimshaw, G. (2010). The relationship between hand preference, hand performance and general cognitive ability. Journal of the International Neuropsychological Society, 16, 585-592.
Johnston, D., Nicholls, M. E. R., Shaw, M., & Shields, M. (2009). Nature’s experiment? Handedness and early childhood development. Demography, 46, 281-301.
Nicholls, M. E. R., Orr, C. A., & Lindell, A. K. (2005). Magical ideation and its relation to lateral preference. Laterality, 10, 503-515.