A life-history perspective on body mass: Exploring the interplay between harsh environment, body mass, and mating success.

Previous research has revealed the importance of body mass for biological fitness. However, studies that explore body mass index (BMI) in life-history perspective are still scarce. In the present research, we tested the hypothesis that a harsh environment facilitates faster growth, thus resulting in higher BMI; consequently, higher BMI should be related to fitness-related advantages, especially in individuals who grew up in a harsh environment. The research is conducted on a community sample of young adults (N = 218). In addition to BMI, we measured economic poverty and family dysfunctions as indicators of environmental harshness. A composite measure of short-term mating and the early onset of sexual activity was used as an operationalization of mating success, representing a fast life-history behavioral pattern. The results showed that BMI was positively related to environmental harshness and mating success; furthermore, a harsh environment and mating success were also positively associated. Finally, an interaction between BMI and poverty was detected: Mating success was especially highly pronounced in individuals with elevated BMI who grew up in conditions of economic scarceness. The results are in line with life-history theory, especially with developmental theories of psychosocial acceleration. Study findings suggest that higher BMI is a part of a fast life-history pathway, and it represents an adaptive morphological response to harsh environment. (PsycINFO Database Record (c) 2018 APA, all rights reserved)