Mensa often gets enquiries as to which we have more of - left handed members or right handed members? And whether which hand you use is linked to IQ. 

So we recently began to collect statistics from new members. With the information collected so far 10.58% of new members are left handed and 89.42% are right handed. This appears to reflect estimates of the UK population as a whole. 

Of course the data does not cover membership as a whole, and Mensa members do not represent everyone with a high IQ. However it seems that what hand you use does not necessarily correlate with IQ.