14 Part 1 Foundations of Human Development
Lastly, and again related, is the issue of motivation. Who directs people’s growth
and development? Do people direct themselves through exploration and interactions?
Do others, such as parents, teachers, and friends, direct growth and development? These
three issues continue to be the subject of debate and controversy.
Nature Versus Nurture
How do you describe yourself to others? Are you outgoing? Are you shy?
Do you have brown hair and eyes? How might you describe your body type? Are
you thin or are you heavy? You have many traits, abilities, and tendencies. Some
of these you may attribute to genetics. Others you assign to your environment.
If you have brown eyes, you may credit this
to your father. You are likely correct since eye color
is an inherited trait, 1-9. If you are thin, you may
credit this to your mother. Could your weight,
however, have more to do with your eating habits
than heredity? Perhaps you eat healthful foods
such as fruits and vegetables and avoid junk foods
high in sugar and fat. You are also physically
active every day. If you were not carefully moni-
toring your weight, would you still be thin? Body
dimensions and traits may be easier to trace to
genetic or environmental influences, but for many
traits, identifying the source can be difficult.
The debate between genetic versus envi-
ronmental influences on development is often
called the nature versus nurture debate. This is
the choice between heredity as a source of your
development and the environment. Tremendous
progress in the last two decades has helped
identify traits more influenced by heredity and
those influenced more by environment. For most
traits, other than physical characteristics such as
eye and hair color, both genetics and environ-
ment play a part. The next chapter will cover the
issue of nature versus nurture in more depth.
Nature Versus Nurture
Imagine Cara, a shy and reserved girl, sitting in class nervously waiting for her
turn to read aloud. Next to her sits her classmate Kenny, who is bursting with energy
and can hardly wait for his turn to read. When Kenny’s turn comes, he speaks loudly
and confidently, even when he stumbles over words.
• Were Cara and Kenny born that way?
• Was Cara taught to be shy by her shy parents? Is shyness a natural part of who she is?
• If Kenny were born with a tendency to be shy, would he have been as outgoing if
raised in Cara’s family rather than his own?
Case Study
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1-9
This teen has similar physical features as
her father.