REVERSALS IN COMPLEXITY

On the Complexity Theory of Language Acquisition, structures that are more complex and difficult are acquired after structures that are less complex and difficult. Here, "complexity" (C) is defined as the information differential between an earlier and a later stage in a tree — typically, the total number of its binary branchings — and "difficulty" (D) is defined as the total number of its branches. The members of a pair of structures, (SI, S2), accordingly undergo a reversal in C and D when the C and D of S1 is greater than the C and D of S2 at an earlier point in time, but the C and D of S1 is less than the C and D of S2 at a later point in time, i.e. when first Cl, Dl (SI) > C2, D2 (S2), then C2, D2 (S2) > Cl, Dl (SI).