First records of sinistrality
in the hogchoker, Trinectes maculatus (Bloch and Schneider) and partial albinism within a reversed American Heterostomate.
Is forced dextrality an explanation for the fall in the prevalence of sinistrality
This survival advantage allows sinistrality to spread throughout previously dextral populations.
And a DNA-based family tree of the snail genus showed that sinistrality has arisen independently at least six times in Satsuma, more than would be expected were there not some driving force behind its evolution.
This suggests that maternal, rather than paternal sinistrality, is associated with the elevated incidence of left-handed sons issuing from LL couples, the generally higher incidence of left-handed sons to LL couples possibly, therefore, being due to maternal sinistrality plus a minor base rate increment attributable to either dextral or sinistral fathers.
Essentially, the critical differences between prior and present results occur with respect to the influence of paternal sinistrality. In the present sample left-handed mothers produced the highest incidence of sinistral sons and left-handed fathers produced the lowest incidence of sinistral sons, the rate for the latter being no different than that for right-handed fathers.
Whereas Levy suggested that dextrality was favourable for spatial abilities and sinistrality
favourable for verbal abilities, Annett's theory suggests (Annett, 1995, [ILLUSTRATION FOR FIGURE 3 OMITTED], p.
One should also note that Casey, Colon & Goris (1992) have suggested that right-handed females with familial sinistrality
are most likely to benefit from such training.
It should also be noted that the presence of a balanced polymorphism for the rs system as a whole does not mean, as Annett (1985) puts it, 'that there must be advantages associated with sinistrality
We must therefore conclude that there is no convincing evidence, despite a wealth of intriguing folkloric and etymological evidence, that modern-day Kerrs and Carrs have an increased likelihood of sinistrality