In our paper "Parent-offspring conflict and cost-benefit analysis in adolescent suicidal behaviour", we identified a pattern in suicidal behaviour related to the birth order of siblings. Parental investment is a limited resource spread between all offspring in order to maximize reproductive success, and the birth order of offspring affects the attention that they receive, as well as attention-seeking behaviour. We found that middle-borns are less likely to attempt suicide but are more likely to make riskier attempts on their lives. Since the middle child is often left in an unfavourable position in gaining parental investment, these findings support the theory that suicide threats and attempts can be used to leverage attention and sympathy, as well as to compel significant social partners to provide help and support. By conducting cost-benefit analysis, we found that a middle child may need to take riskier action in order to leverage more parental investment than their firstborn or lastborn siblings.
- "Parents and Children in Conflict" – Psychology Today