"The empathizing–systemizing (E-S) theory suggests that people may be classified on the basis of their scores along two dimensions: empathizing (E) and systemizing (S). It measures a person's strength of interest in empathy (the ability to identify and understand the thoughts and feelings of others and to respond to these with appropriate emotions); and a person's strength of interest in systems (in terms of the drive to analyse or construct them). A system is anything that follows rules. Key classes of systems including mechanical systems, natural systems, abstract systems, and collectible systems. Rules in turn are defined as repeating, lawful patterns."