ABSTRACT
The relationships between a set of birth-risk factors, i.e., sex, parity, and maternal age, and handedness were computed for 600 elementary school children. None of these birth-risk variables (or relevant combinations of them) were significantly related to handedness. These data further question the validity of the hypothesis that left-handedness results from stressful prenatal and birth conditions.
Subject(s)
Functional Laterality , Infant, Newborn, Diseases , Adult , Child , Female , Humans , Infant, Newborn , Male , Maternal Age , Parity , Risk , Sex FactorsABSTRACT
The handedness distribution of a group of 578 gifted elementary school children (I.Q. = 132) was compared to handedness distribution of 391 non-gifted children (I.Q. less than 132), with the result that the gifted group was significantly less right-handed than their non-gifted peers. These data were discussed relative to Bakan's hypothesis that left-handedness results from stressful prenatal and birth conditions. In addition attention was paid to the possibility of a non-linear relationship between intelligence and degree of right-handedness.
Subject(s)
Functional Laterality , Child , Child, Gifted , Humans , Stanford-Binet TestABSTRACT
In an attempt to clarify the relationship between self-reported birth complications and handedness, the handedness distributions of 181 college students who reported birth complications and 1320 students who reported no complications were compared. The results suggest a clear but modest shift in the birth complications group away from the dextral end of the continuum. However these data did not validate the hypothesis that left-handedness results from birth complications.
Subject(s)
Functional Laterality , Infant, Newborn, Diseases , Adolescent , Adult , Humans , Infant, NewbornABSTRACT
Recently Leviton and Kilty reported that the birth dates of left-handed girls in elementary school display a seasonal trend which peaks in November. We report here a failure to replicate this finding for 257 male and 323 female college students. Further, we have considered the likelihood that the original finding was due to sampling error rather than speculating that environmental factors associated with the season of birth are implicated in the etiology of left-handedness, as Leviton and Kilty have stated.
