The Evolutionary Approach

15
Approaches to the Science of Psychology
THE BIOLOGY OF EMOTION Robert
Levenson, a psychologist at the University of California at Berkeley, takes a biological approach to the study of social
interactions. He measures heart rate,
muscle tension, and other physical reactions as couples discuss problems in their
relationships. He then looks for patterns
of physiological activity in each partner,
such as overreactions to criticism, that
might be related to success or failure in
resolving their problems.
researchers try to identify changes taking place in the brain as information is stored
there. (Figure 6.13, in the chapter on memory, shows an example of these changes.) And
when studying thinking, they might look for patterns of brain activity associated with,
say, making quick decisions or reading a foreign language. Research discussed in nearly
every chapter of this book reflects the enormous influence of the biological approach
on psychology today.
The Evolutionary Approach
Mothers are solely
responsible for the care and protection of
their young in almost all species of mammals. These species survive without male
parenting, so why are some human
fathers so active in child rearing? Do
evolutionary forces make fathering more
adaptive for humans? Is it a matter of
learning to care? Is it a combination of
both? Psychologists who take an evolutionary approach study these questions
and others relating to the origins of
human social behavior.
A FATHER’S LOVE
evolutionary approach A view that
emphasizes the inherited, adaptive
aspects of behavior and mental
processes.
Biological processes are also highlighted in an approach to psychology that is based on
Charles Darwin’s 1859 book, The Origin of Species. Darwin had argued that the forms
of life we see today are the result of evolution—of changes in life forms that occur over
many generations. He said that evolution occurs through natural selection, which promotes the survival of the fittest individuals. Those whose behavior and appearance
allow them to withstand the elements, to avoid predators, and to mate are able to survive and produce offspring with similar characteristics. Those less able to adjust, or
adapt, to changing conditions are less likely to survive and reproduce. Most evolutionists today see natural selection operating at the level of genes, but the process is the
same. Genes that result in characteristics and behaviors that are adaptive and useful in
a certain environment will enable the creatures that inherited them to survive and
reproduce, thereby passing those genes on to the next generation. According to evolutionary theory, many (but not all) of the genes that animals and humans possess today
are the result of natural selection.
The evolutionary approach to psychology assumes that the behavior and mental
processes of animals and humans today is largely the result of evolution through natural
selection. Evolutionary psychologists see aggression, for example, as a form of territory
protection, and they see gender differences in mate selection preferences as reflecting
different ways of helping genes to survive in future generations. The evolutionary
approach has resulted in a growing body of research (Buller, 2005; Buss, 2004a); in later
chapters, you will see how it is applied in relation to topics such as mental disorders,
temperament, interpersonal attraction, and helping.