Country mouse on sibling rivalry

I muse that there must be a Darwinian reason for sibling rivalry as I help myself to some more chicken and cashew nuts. I’ve already finished the prawn crackers, the spare ribs and the lemon chicken. The note on the kitchen table from the children’s mother could not be clearer: ‘Please tidy the kitchen.’ They hadn’t. One son claimed to have moved his breakfast plate 3in closer to the sink than the other, and the resulting argument was resolved by them both halting any attempt to clear up, leaving the remains of breakfast and lunch in limbo.

For effect, they had also started yelling about saucepans at each other as soon as I walked in the door, but this was nothing compared to their shock when, in my own fit of pique, I refused to let them eat any of the takeaway. It was a lot to eat. I struggled through the beef with black bean sauce with stubborn determination before bringing in the terriers as reinforcements to finish off the remains.

By then, sibling rivalry had also gone to the dogs, to be replaced with something altogether more frightening, two teenagers united against their parent. I wonder what Darwin’s theory for that is?