Birth Order and Left-Handedness

Abstract

In an extensive review of patients with unilat¬ eral exophthalmos, Van Buren et al' refer to a group of patients whose proptosis resulted from venous hypertension. They note that asymmetric compression of the orbital venous drainage through the cavernous sinus should be a rare mechanism in view of the relatively free collateralization in this region. However, there are indi¬ vidual cases in which this mechanism has been well documented, especially in sellar and parasellar lesions.In our patient, the third ventricle may have acted as an intrasellar mass, causing both optic chiasm and cavernous sinus compression. The dramatic response of this patient's signs to cerebrospinal fluid diversion and their return with shunt malfunction suggest that the findings of unilateral proptosis, visual field defect, and hydrocephalus are interrelated.

The effects of specific birth stressors on four indexes of lateral preference.

“…There is one important variable that we have not yet considered, namely the sex of the offspring. Most of the studies reporting significant relationships between birth complications and patterns of lateral preference have noted that many of the effects seem to be sex-related, with males displaying a higher probability of sinistrality when birth complications are present (Bakan, 1971;Leviton & Kilty, 1976;Smart et al, 1980). Therefore, we decided to analyze males and females separately.…”

“…Unfortunately, confirmation of Bakan's initial findings has not been obtained easily. With the exception of Leviton and Kilty (1976), who did not report on the statistical robustness of their results, studies attempting to replicate Bakan's original findings, utilizing selfreported birth stress and/or birth order data, have had no success (Hicks, Pellegrini, & Evans, 1978;Hubbard, 1971;Schwartz, 1977;Searleman, Tsao, & Balzer, 1980).…”

Left-handedness: A marker for decreased survival fitness.

“…There have been a number of recent studies that have observed that left-handedness is more prevalent in samples of individuals who have experienced stressful births. Individuals with a history indicating premature birth, prolonged labor, low birth weight, RH incompatibility, breech delivery, multiple birth, and several other birth stressors are more likely than others to deviate from the population norm of right-handedness (Ashton, 1982; Badian, 1983; Bakan, 1977; Bakan, Dibb, & Reed, 1973; Coren & Porac, 1980a; Coren, Searleman, & Porac, 1982; Leviton & Kilty, 1976; Smart, Jeffery, & Richards, 1980). This relationship is not limited to handedness, but seems to generalize over most of the lateralized behaviors, including foot, eye, and ear preferences as well (Coren & Porac, 1980a; Coren et al 1982).…”

Relationship between birth order, birth stress, and lateral preferences: A critical review.

“…Bakan et al (1973) reported that 510 college students completed the questionnaires used to obtain the data; however, 112 of these students were excluded from final analyses without explanation. Leviton and Kilty (1976) reported that 104 of 592 subjects tested repeated a grade in school. Therefore, a substantial number of their subjects may have had low intelligence or learning disabilities.…”