Their study, forthcoming in the Journal of Consumer Research, found participants preferred to enroll a daughter rather than a son in beneficial programs, preferred to give a U.S. Treasury bond to a daughter rather than a son, and bequeathed a greater share of their assets to female offspring in their will when they perceived economic conditions to be poor. This research draws on theory in evolutionary biology suggesting that investment in female versus male offspring depends on resource availability.  Abstract 
 
 Although parents often try not to favor one child, we examine whether specific environmental factors might bias parents to favor children of one sex over the other.
– "Almost all parents say that they don't favor one of their children over another," says the lead author of a new study that shows that sentiment flies out the window when times get tough, because "economic recessions subconsciously lead parents to prefer girls over boys." The idea, per the study in the Journal of Consumer Research, is that parents are instinctively inclined to help the survival of their species, and, as another researcher adds, "when resources are scarce, parents prefer females because they have a larger reproductive payoff. Almost every female child will produce some offspring, but many male children end up having zero offspring." To test this bias in humans, researchers enlisted 629 people and showed them a news article that described the economy as neutral, getting better, or getting worse. Asked to divide their assets between an imaginary daughter and son, as well as assign one to a benefits program, the split was 50/50 when times were good or neutral, but 60/40 in favor of daughters when the economic forecast was bleak, reports Phys.org. And as those kids approached reproductive age, the bias sharpened. "It's very clear (parents) want to treat their children equally," says a third researcher. "But if they're relying on feelings for how they're allocating resources, it's very likely this bias is seeping in, especially when ... they don't have money to do everything." (Meanwhile, daughters of working moms make more money.)