The social supports of suicide attempters: The different roles of family and friends

The social support patterns of a sample of 101 suicide attempters were compared with the patterns of a control sample on the basis of structured interview data. Network characteristics and the extent of support in different functional categories were examined as to their absolute and relative power to discriminate between the suicide attempters and the controls. A clear separation of the functions of kin and of friends/acquaintances emerged. The crucial difference between the attempters and the controls lay in the number of friends with whom the subjects had agreeable everyday interactions and in the number of kin that provided crisis support, both psychological and instrumental. Other support differences between the two groups were of secondary importance. While there was no overall difference in the frequency of social interactions between the two groups, the size of the social network differed greatly. Consequences for the conceptualization and measurement of social support as well as for the prevention of suicidal behavior are discussed.     

Bias in the use of base rates: Racial prejudice in decision-making

Two studies investigated biases in the use of base rate information when assessing the probability of a witness' accurate identification of a white or West Indian as a burglar. An adapted version of the Kahneman-Tversky cab problem was used, to provide a social decision in which biases could be measured against some normative standard. Ethnicity of youth (white/West Indian) and nature of base rate (incidental/causal) were manipulated in a 2 × 2 between-subjects design. A significant interaction effect revealed that subjects took no account of the base rate for a West Indian subject, but used the base rate only when it was causal and the youth was white. This ‘prejudice effect’ against a West Indian youth and ‘exoneration effect’ for a white youth were replicated in a second study, using a microcomputer and chronometric analyses. Results are discussed in terms of heuristic decision-making, social schemata, and the cognitive versus motivational bases of bias in the use of base rates.