Who Needs Emotions? The Brain Meets the Robot

38 brains
Although instinctual behaviors in animals may not reflect the complexity
of human emotions, the origin of the word instinct, from the Latin instiguere
meaning “to incite, to impel,” reminds us of the Latin origins of the word
emotion (“to move out”) and suggests a conceptual link between instinct and
emotion. An early observer of behavior in animals, McDougall, postulated
this close relationship between instinct and emotion. He conceptualized each
instinct as
an inherited or innate psychophysical disposition to perceive, and to
pay attention to, objects of a certain class, to experience emotional
excitement of a particular class, and to experience an emotional excitement
of a particular quality upon perceiving such an object and
to act in regard to it in a particular manner, or at least, to experience
an impulse to such action. (McDougall, 1908)
Impressive examples of the primitive roots of complex motivated behavior
are found in the wonderful observations of lizard behavior by Paul MacLean
(1990), who worked in the Laboratory of Brain Evolution and Behavior at the
National Institute of Mental Health throughout the middle part of the last
century. Based on the writings and extensive observations of ethologists, as
well as his own work, MacLean brings to our attention the daily behavioral
patterns of the rainbow lizard, a six-inch lizard from West Africa, and the giant
komodo dragon, an Indonesian lizard that grows up to 10 feet in length.
The daily routines, subroutines, and use of signature displays for social communications
are described in detail. In the morning, the typical male rainbow
lizard emerges from his safe, protected niche, warms himself, attends to his
toilet, and then goes off to forage and feed on insects. If he has established
territorial rights, he will display brilliant red and blue colors rather than drab
brown. Depending on what and who he encounters, he wards off male intruders
into his space by very particular signals (nodding and pushups) and, if
left in peace by other males, engages in courtship and possibly copulation with
a willing female, exemplified by neck biting and wrapping his leg around her
to facilitate mating. At the end of the day, the lizard retires and the next day
the routine repeats itself. One sees the fixed, routine patterning as well as the
modifiability and flexibility in the expression of these behaviors. For example,
in the male blue spiny lizard defending its territory, there are degrees of aggressive
display depending on the nature of the encounter. If the intruder
merely approaches, there is a “warning, take-notice” display. If the intruder
does not heed this, there is a “challenge” display, in which the lizard expands
various aspects of his body to make it larger and exposes the blue coloration
on his belly. If the intruder still fails to retreat, the tenant rushes for him, taillashes,
and bites the tail of the offending conspecific (sometimes tails are lost).
One way or another, the encounter ends with one member engaging in a sub-