Certainly, the denser population doesn't help. But on average I think British people tend to litter more, destroy public property etc.
I had never heard of the term "anti-social behaviour" until I moved here.
Don't get me wrong, there are many, many brilliant things about the British and the UK as well. I just wish more people cared - like how does the public not react with outright fury when a company yet again dumps sewerage into waterways, as they have done several times before - and that company is given a slap on the wrist (fine) rather than obliterated & replaced with a scorched Earth policy as it's completely unacceptable.
And those same people who are apathetic to such things say stuff like "oh I wouldn't do that...the canals and rivers are gross and filled with bacteria and rubbish" when I tell them I'm going kayaking or canoeing. Like...be proud of your country! Be swift & decisive when companies pollute the water, or members of the public break something or cause public disorder.