Childlessness and investment in nieces, nephews, aunts and uncles in Finland.

Kin selection theory predicts that individuals may increase their inclusive fitness by investing in their genetically related kin. In addition, according to the reproductive value hypothesis, individuals may increase their fitness more by investing in their kin in descending rather than ascending order. The present study uses the Generational Transmissions in Finland data collected in 2012 (n ¼ 601 women) and analyses whether childless younger women invest more in their kin than younger women with children. The study finds that childless women are more likely than mothers to invest in their nieces and nephews but not their aunts and uncles. Thus the results are in line with the reproductive value prediction.