Suicide and Homicide Rates in Canada and the United States

Suicide and homicide rates by age were analyzed for Canada and the United States, indicating that suicide is higher in Canada and that homicide is higher in the United States. Results indicated a positive association between homicide and suicide rates in the United States but these two rates of death were not significantly associated in Canada. Holinger (1987) had associated the relative size of the cohort to the rates of suicide and homicide in young people in the United States. The more current data in both countries did not support Holinger's results. Using the measure devised by Easterlin (1980) and Ahlburg and Schapiro (1984) –that is, the proportion of youths aged 15–24 relative to adults aged 25–64–the correlation between the size of the youth cohort and the suicide rate of youths aged 15–24 was negative. It is concluded that the two patterns in these two countries may be explained from a historical perspective.     

Physiological foundations of behaviour

Ohne Zusammenfassung

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Physiological foundations of behaviour

     

Genetic and environmental factors in orientation anisotropy: a field study in the British Isles

Visual acuity for the detection of gratings at four orientations was measured for groups of ten boys and ten girls aged five to seven years, from the following four populations: Scots in Glasgow, Pakistanis in Glasgow, Gaels in Stornoway (Outer Hebrides) and East Anglians in Littleport (Cambridgeshire fenlands). The Glaswegians, both Scottish and Pakistani, showed the normal pattern of anisotropy, with poorest acuity for oblique orientations; the East Anglians showed no significant anisotropy; while the Gaels were unusual in showing poorest horizontal acuity. A group of fourteen Pakistani children in Stornoway differed slightly from a matched group of Gaels. The group differences bore little relation to the visual environments, and were probably due to genetic or cultural factors. The relatively poor horizontal acuity of the Gaels was not correlated with astigmatism. Sex differences were also found, with the boys showing higher mean acuity and a higher ratio between vertical and oblique acuity.