The information correlation functions 
, according to the interpretation of section 3.13, may be seen as the information between these spins. The graph of figure 8.18 for the two spin system, figures 8.19-8.20 for the three spin system, and figures 8.21-8.23 for the four spin system indicate regions of temperature and external field where the distribution of subsets of spins in these systems carries new information not contained in smaller subsets, and where the subset distributions are redundant to smaller subset distributions. (Note that the logarithms are base e, and that 
appears as b in the axis label.) Comparing figures 8.21-8.23, it is clear that the full system distribution is needed to describe the low temperature and small field antiferromagnetic regions. In these regions at each order lower than the number of spins there is structure having to do with the transitions that cannot be captured by still lower order distributions. The ferromagnetic side of the graphs appears far simpler, with almost all of the structure being captured by the lower order distributions (the first order information correlation is the first order negentropy). In a single system there are thus two regions where the behavior of the information correlation functions is vastly different, and where the complexity of the description needed is therefore vastly different.
Figure 8.18: Second order information correlation for the 2 spin case.
Figure 8.19: Second order information correlation for the 3 spin case.
Figure 8.20: Third order information correlation for the 3 spin case.
Figure 8.21: Second order information correlation for the 4 spin case.
Figure 8.22: Third order information correlation for the 4 spin case.
Figure 8.23: Fourth order information correlation for the 4 spin case.