Why 2 + 2 = 5 looks so wrong: On the odd-even rule in sum verification

The odd-even status of a sum depends on the odd-even status of its addends. A sum must be odd if an odd number of its addends are odd; else it must be even. A proposed sum that violates the required odd-even status of the sum—that is, deviates from the correct sum, whether odd or even, by an odd value (e.g., splits of ±1, ±3, ±5)—can be rejected immediately as false. Subjects in the present study did indeed use the odd-even rule in sum verification, because they were as fast and accurate in rejecting a split of ±1 as one of ±2, and a split of ±3 as one of ±4, even though a larger split generally is easier to reject (symbolic distance effect), and splits of ±3 and ±4 were rejected faster and more accurately than those of ±1 and ±2. Performance on separate odd-even tasks indicated that the odd-even properties of numbers and sums are readily available for use by adults, and that persons who do well on such tasks are especially likely to use the odd-even rule in sum verification.     

A note on McDonald's generalization of principal components analysis

It is shown that McDonald's generalization of classical Principal Components Analysis to groups of variables maximally channels the total variance of the original variables through the groups of variables acting as groups. A useful equation is obtained for determining the vectors of correlations of theL2 components with the original variables. A calculation example is given.     

Information and the memory span

Messages differing in number of symbols and symbol information load were presented tachistoscopically to 4 adult Ss. The messages were constructed by random drawing with replacement from an alphabet of 8 black form symbols and an alphabet of 32 colored form symbols. The number of symbols recalled varied as a function of alphabet; however, the information in recall was constant for all conditions. The number of symbols recalled and the information in recall was independent of message length.     

On the disunity of the self: A systems theory of personality

The views of a variety of theorists who have proposed that the mind may be usefully conceptualized as made up of a set of subselves are reviewed, and several principles are proposed for a possible systems theory of personality.     

Ecological correlates of adolescent attempted suicide

Rates of adolescent attempted suicide were correlated with social indicators over the electoral wards of Edinburgh (Scotland). Rates were found to be higher in wards where child neglect and misbehavior were more common. Rates of attempted suicide in the total population also were related to the housing pattern/social class of the wards. The importance of identifying similarities and differences in the patterns of suicidal behavior of adolescents and adults was noted.     

Teenage suicide in Zimbabwe

The teenage suicide rate in Zimbabwe did not change much during the 1970s, though the rate rose for female teenagers. Female teenagers used poison as a method of suicide more often than did adults, and self-immolation had increased in frequency among young women by the mid-1980s.     

The relevance of Ellis's neurohormonal theory of crime and delinquency to suicide

Ellis's neurohormonal theory of criminality is briefly reviewed, and its relevance for understanding suicidal behavior is explored. It was found that many variables identified by Ellis as characteristic of criminals are also characteristic of suicidal individuals. In addition, Ellis's perspective identified many issues that have been explored only cursorily or not at all by suicidologists. Ellis's theory may, therefore, have heuristic value for suicidology.