The trait sets of Bold/Timid and Serious/Playful can be observed in infants early in their development. The box below describes the natural development of the four basic types when no conditioning has occurred to alter it.
By Nature:
C - Bold, serious infants tend to become Extroverted-Thinking-Intuitive adults (Commanders)
O - Timid, serious infants tend to become Introverted-Thinking-Sensing adults (Organizers)
R - Timid, playful infants tend to become Introverted-Feeling-Sensing adults (Relaters)
E - Bold, playful infants tend to become Extroverted-Feeling-Intuitive adults (Entertainers)
The influences of nurturing or conditioning
can, and often do, alter the natural development of tendencies and preferences.
Field observations and extensive studies suggest that when conditioning
or negative nurturing has not interfered with natural development, the
above correlations hold true. Further research suggests that when individuals
move away from negative conditioning and back to their natural functioning
mode, the functions again correlate with reported and observable behaviors
and traits.
Recent brain research reveals that the way the brain is segmented and
connected makes it physiologically, as well as psychologically, impossible
for oppositions to exist as true combinations. Oppositions exist as a
result of negative conditioning, which usually occurs early in childhood,
and are not natural occurrences.