Advancing the study of fitness-related motivational forces: The links between reproductive motivation and fundamental social motives

Fundamental Social Motives are the most prominent taxonomy of human motives developed using an evolutionary framework. While covering several motives related to evolutionary fitness, this taxonomy does not cover an additional motivational force closely associated to fertility ? reproductive motivation. In the present research, we explored the relations between Positive and Negative Childbearing Motives, Fundamental Social Motives, and planned number of children and age of first reproduction as the proxies for reproductive fitness. The results showed that reproductive motivation largely falls outside the latent structure of Fundamental Social Motives (the only exception was Affiliation Independence which loaded on Negative Childbearing Motives), hence, they represent distinct motivations. The network model showed that Positive and Negative Childbearing Motives have different but conceptually meaningful associations with Fundamental Social Motives. Positive Childbearing Motives are strongly positively related to Kin Care Family, followed by Mate Retention Breakup Concern, while the Negative Childbearing Motives have the highest associations with Affiliation Independence, Self-Protection, Status seeking, and Affiliation Exclusion. Finally, regression models showed that reproductive motivation has additional predictive abilities in explaining the variation of planned number of children and age of first reproduction compared to Fundamental Social Motives. We believe that the current data suggest the fruitfulness of examining reproductive motivation together with the Fundamental Social Motives. This would enhance the ability of evolutionary social scientists to examine and explain current behavioral evolution.