controlling the reflex and physiological operations are least easily
modified, while those controlling the higher mental processes are most
easily modified. The neurone groups controlling the instincts hold a
middle place. So far as permanence goes, connections between
sensorimotor neurone groups seem to hold modifications longer than do
connections between either associative-motor or associative-association.

It is probably because of this fact that habit in the minds of so many
people refers to some physical activity. Of course this is a
misconception. Wherever the nervous system is employed, habits are
formed. There are intellectual, moral, emotional, temperamental habits,
just as truly as physical habits. In the intellectual field every
operation that involves association or memory also involves habits. Good
temper, or the reverse, truthfulness, patriotism, thoughtfulness for
others, open-mindedness, are as much matters of learning and of habit as
talking or skating or sewing. Habit is found in all three lines of
mental development: intellect, character, and skill.

Not only does the law of habit operate in all fields of mental activity,
but the characteristics which mark its operation are the same. Two of
these are important. In the first place, habit formation results in a
lessening of attention to the process. Any process that is habitual can
be taken care of by a minimum of attention. In other words, it need no
longer be in the focal point, but can be relegated to the fringe. At the
beginning of the modification of the neurone tract focal attention is
often necessary, but as it progresses less and less attention is needed
until the activity becomes automatic, apparently running by itself. Not
all habits reach this stage of perfection, but this is the general
tendency. This lessening of the need for attention means that less
energy is used by the activity, and the individual doing the work is