To what extent do we continue to change and develop during adulthood? Which capacities appear to remain static during adulthood and which seem to be fluid? Classify them in reference to psychoanalytical theory.

The correct answer to this open question is the following.

Without a doubt, we continue to change and develop during adulthood.  According to the theory, the capacities that appear to remain static during adulthood are the capacity to increase reason, the capacity to learn new and different things, and the capacity to solve abstract problems. However, recent studies have shown that Cristalized Intelligence continues in adulthood. This intelligence allows adults to better use their accumulated intelligence through the years and that skills and abilities can be used effectively. Researchers affirm that Cristalized Intelligence keeps on growing with the pass of the years. Raymond Cattell and John Horn are two of the authors that have studied these concepts.