While maybe not essential, the "anti-" aspect of the correlations induced by anthropic selection bias at least seems important. Obviously, the appropriate changes of variables can make any particular correlation go either positive or negative. But when the events all measure the same sort of thing (e.g., flooding in 2014, flooding in 2015, etc.), the selection bias seems like it would manifest as anti-correlation. Stretching an analogy beyond its breaking point, I can imagine these strange anti-correlations inducing something like anti-ferromagnetism.