The biological framework
Energy spent on one function is unavailable for another, which creates trade-offs. Stephen Stearns and others have examined these trade-offs through traits such as age at maturity, number of offspring, and lifespan. A central finding is that high external mortality can favor earlier reproduction, as long-term investment may never pay off.
- Current versus future reproduction
- Quantity versus quality of offspring
- Growth versus immediate survival
Use in psychology
Belsky, Steinberg, and Draper proposed in 1991 that childhood adversity might orient development toward earlier puberty and sexual activity and less stable relationships. Ellis and colleagues distinguished two features of risk in the environment: harshness and unpredictability. Psychologists often describe a faster or slower life-history strategy, measured by questionnaires about personality and planning.
Disputes
Nettle and Frankenhuis argue that psychological and biological uses of the theory have diverged, and that the former sometimes relies on a single fast-to-slow continuum that biology does not firmly support. Self-report scales have been questioned as measures of strategy. It is also hard to separate adaptive development from harm caused directly by poverty or stress, and from genetic influences shared between parents and children. Framing behaviors as a strategy does not make them good, inevitable, or a suitable basis for labeling any group.
Further reading
- Belsky, J., Steinberg, L., & Draper, P. (1991). Childhood experience, interpersonal development, and reproductive strategy: An evolutionary theory of socialization. Child Development, 62(4).
- Ellis, B. J., Figueredo, A. J., Brumbach, B. H., & Schlomer, G. L. (2009). Fundamental dimensions of environmental risk: The impact of harsh versus unpredictable environments on the evolution and development of life history strategies. Human Nature, 20(2).
- Nettle, D., & Frankenhuis, W. E. (2020). Life-history theory in psychology and evolutionary biology: One research programme or two? Philosophical Transactions of the Royal Society B, 375(1803).