Developmental psychology.pdf

310 Motivation and Emotion
3. As one proceeds up the evolutionary scale, there is decreasing evidence for
instinctive behavior. The term generally is not applied to human beings, and
animal investigators now speak of species-specific behaviors instead.
Motives for Survival
4. At the human level sexual behavior illustrates the relationship between
inborn and acquired factors in human motivation. It is prompted by
hormonal secretions, androgen and estrogen, but has an extremely
important basis in learning. Similarly, maternal motivation is related to the
secretion of prolactin in animals, but among human beings culture again
plays a very large role in the development and modes of satisfaction of this
form of motivation.
5. The biochemical basis of hunger involves conditions of the stomach, blood,
and also the hypothalamus. The lateral area of this organ seems to play an
important role in initiating eating, whereas the ventromedial nucleus is
involved in its cessation. The specific ways in which the hunger drive is
satisfied are significantly influenced by learning.
6. The most obvious symptom in thirst is dryness of the mouth and throat, but
to be effective in reducing thirst, water must alleviate cellular dehydration
in other areas, including the hypothalamus. Again, learning plays a role in
our preferences and modes of drinking.
7. Prolonged lack of sleep leads to perceptual disturbances, loss of emotional
control, and decreased intellectual functioning, but sleep is not a totally
passive state. It is induced by activities in certain brain regions, especially
the thalamus and reticular formation, and various levels of activity occur at
the different stages of sleep. During dreaming, breathing is heavy and
irregular, blood pressure is increased, and the electrical activity of the brain
is at a very high level.
Motivation for Stimulation
8. Many organisms seek types of stimulation for which no physiological bases
have been established, although the motives appear to be part of our
biological inheritance. For example, most higher organisms desire variation
in sensory stimulation, sometimes referred to as sensory-variation motives.
The extensive exploratory and manipulatory behaviors of primates,
including human beings, illustrate the associated behaviors. For most
human beings, sensory constancy is an aversive state.
9. Animals and human beings also desire affectional stimulation, which is
called contact comfort when the tactual element is emphasized. It includes
warmth, cuddliness, and hugging, and studies with animals indicate that
such contact is essential for adequate social and sexual development.
Observations of human beings suggest that it also plays an important role in
ensuring normal human development.
Theory and Perspectives
10. The concept of drive reduction, although useful in understanding the basis
of individual survival motives, is not readily applied to motives for sensory
variation and affectional stimulation. Instead, motivated behavior is
sometimes said to follow this goal-directed sequence: a physiological need or
imbalance occurs in the organism; it produces a state of arousal known as a
drive; the driven organism is ready to respond to incentives, which are
related to its aroused state; and these incentives can serve as rewards for
the organism that acquires them.