This chapter will examine what Pareto said concerning each of the individual
differences which align to form his psychological model. It will consider how well
these differences match up with constructs which have subsequently developed
within psychological and sociological literatures, and it will call upon wide-ranging
evidence to assess the extent to which they align as Pareto envisioned. For this task
to remain manageable, it has been necessary to focus upon what seem to be the
model’s core individual differences.