Test of Joiner's Theory

Joiner's (2005) theory suggests that there is a key difference between those who attempt and those who complete suicide. Although both attempters and completers have a desire for death, Joiner proposes that only those who complete suicide have acquired the ability to end their lives. He posits that one can acquire the ability for completed suicide through exposure to painful and provocative experiences, including previous suicidal behavior. Two other variables are posited to contribute to an individual's desire, but not ability, for suicide completion: feelings of burdensomeness and thwarted belongingness. There is evidence, however, that social rejection (i.e., thwarted belongingness) can result in an individual being "numbed" to physical pain (DeWall & Baumeister, in press). This suggests that thwarted belongingness may also contribute to an individual's ability to engage in serious suicidal behavior. The current study compares a group of suicide attempters (n = 97) to a group of suicide completers (n = 86). It was hypothesized that both thwarted belongingness and history of pain exposure would be predictive of an individual's status as a suicide attempter or suicide completer. Results did not conform to prediction: history of pain exposure was not predictive of an individual's status as a suicide completer. Thwarted belongingness, however, was a marginally significant predictor of suicide completion.