Lower Parental Investment in Stepchildren

It seems that children with parents that are still married are provided with more financial support than those with a stepparent involved. Stepparents feel less inclined to provide for their non genetic children than those of parents of equal income with biological children. Furthermore, stepfathers are seen to be more financially supportive to their stepchildren than stepmothers, a social indicator of the providing male figure/part of the mating ritual.

http://www.jsecjournal.com/articles/volume4/issue2/tifferetfinal.pdf