The archaic rules system at Westminster fosters social cliques like in high school comedy Mean Girls, according to Scottish MP Amy Callaghan.The 27-year-old has enjoyed a whirlwind start to her career as the new member for East Dunbartonshire after she caused the biggest upset of the 2019 general election.The former office manager sensationally defeated UK Lib Dem leader Jo Swinson despite being a first-time election candidate for the SNP.But while Callaghan enjoys working on behalf of her constituents, she admits the old-fashioned ways of doing things at Westminster have taken some getting used to.Get all the top Scottish politics news sent straight to your Inbox by signing up to our Politics newsletter.We cover Holyrood, Westminster, and