Empirical Support for an Evolutionary Model of Self-Destructive MotivationR Michael Brown, Stephanie L Brown, Aron Johnson, Berit Olsen, et al. Suicide & Life - Threatening Behavior. New York: Feb 2009. Vol. 39, Iss. 1; pg. 1, 12 pgs

Abstract (Summary) We tested predictions generated from an evolutionary account of self-destructive motivation in two survey studies of 18-24-year-old university students. As hypothesized, hierarchical regressions showed that the positive relationship between perceived burden to family and suicide ideation was amplified for participants with low measured health and romantic relationship satisfaction, and for participants with relatively young mothers. The moderating effect of maternal age was also observed in logistic regressions of suicide attempts. These effects occurred independently of depression, hopelessness, and other relevant extraneous variables. Results have implications for understanding self-destructive motivation, assessing suicide risk, and preventing suicidal thinking and behavior. [PUBLICATION ABSTRACT] Jump to indexing (document details)Full Text(5569 words)

Copyright Guilford Publications, Inc. Feb 2009[Headnote]

We tested predictions generated from an evolutionary account of self-destructive motivation in two survey studies of 18-24-year-old university students. As hypothesized, hierarchical regressions showed that the positive relationship between perceived burden to family and suicide ideation was amplified for participants with low measured health and romantic relationship satisfaction, and for participants with relatively young mothers. The moderating effect of maternal age was also observed in logistic regressions of suicide attempts. These effects occurred independently of depression, hopelessness, and other relevant extraneous variables. Results have implications for understanding self-destructive motivation, assessing suicide risk, and preventing suicidal thinking and behavior.

Viewing suicide from an evolutionary per- spective, deCatanzaro (1986) highlighted con- ditions favorable for the selection of self- destructive motivation: (a) an individual's reproductive value is low (e.g., due to old age, poor health, or inadequate heterosexual relationships), and (b) the individual's contin- ued existence burdens genetic relatives, in the sense that it disadvantaged their reproductive success. Under such conditions, staying alive interferes with the only means of genetic transmission available - kin reproduction.1DeCatanzaro's hypothesis that perceived burdensomeness is associated with suicidality has received support from clinical studies (e.g., Hedberg, Hopkins, & Kohn, 2003; Joiner et al., 2002; Motto & Bostrom 1990; Van Orden, Lynam, Hollar, & Joiner, 2006; Woznica & Shapiro 1990), and from direct tests of his model (Brown, Dahlen, Mills, Rick, & Biblarz, 1999; deCatanzaro 1995; Joiner et al. 2002; Van Orden et al., 2006). However, with the exception of Brown et al. (1999), there have been no published evaluations of the more complex and, in some cases, less intuitive interactive propositions suggested by the model. Indeed, we do not even know whether burden effects are amplified with increases in genetic relatedness to the person burdened, as the model suggests.The present research consists of two studies designed to deal with these gaps in our knowledge by focusing on self-destructive motivation in adolescents and young adults enrolled in college. In this population suicide is second only to accidents in causing death, suicide ideation is widespread, and there are increasing numbers of students who come to school with a history of psychiatric treatment and, therefore, vulnerability to suicide (Haas, Hendin, & Mann, 2003).STUDY 1The first question addressed in Study 1 was whether burden effects are moderated by an individual's reproductive potential (IRP). Based on deCatanzaro's model, we expected a burden IRP interaction, in which perceived (financial and time) burden would be more strongly associated with suicide ideation and attempts when measures of IRP (health, attractiveness, romantic relationship satisfaction) are low than when they are high. Note that Joiner's (2005) theory also expects burden to interact with romantic relationship satisfaction, assuming it taps "thwarted belongingness" which, along with perceived burdensomeness, is hypothesized to affect the "desire" for suicide.The second question was whether burden effects are moderated by a measure of the reproductive potential of the person burdened (i.e., maternal age). We expected a burden maternal age interaction, in which burden effects on suicide ideation and attempts would be most pronounced for participants born to younger mothers; that is, those with the highest likelihood of reproducing. We assumed that any such effects observed at the time of data collection could have as their source a developmental process that started much earlier in the lives of both parent and child. Animal models suggest that young mothers, in particular, are sensitive to offspring-generated cues for interference with mating and other fitness-enhancing behaviors (Clutton-Brock, 1991; Maestripieri & Carroll, 1998), which could lead such mothers to respond in ways that bias offspring toward developing a sense of burdensomeness.METHODParticipantsParticipants were selected from a pool of psychology student volunteers from Pacific Lutheran University on the basis of age (