Most parents would hotly deny favouring one child over another but new research suggests they may have little choice in the matter.
Biologists studying a unique species of beetle that raises and cares for its young have found that parents instinctively favour the oldest offspring.

The University of Manchester research — published in Ecology this month — supports the findings of studies carried out on human families but is significant in that it suggests a wholly natural tendency towards older siblings. [continue reading…]