"In ectomorph-cerebrotonics, "the sensory-receptor properties are well developed. As a consequence however the central nervous system (CNS) is soon overloaded and rapidly tires. The cerebrotonic has the gift of concentrating his attention on the external world as well as on his internal world. His vigilance and autonomic reactivity make him behave in an inhibited and uncertain way: introverted behaviour. He has problems with expressing his feelings and with establishing social relationships, and can very well bear to be alone. The elementary strategies of coping with life are perception, reconnaissance and vigilance, cognition and anticipation, and a certain amount of privacy.""