Cognition: Thinking, Intelligence, and Language 293the defensiveness measure. These same participants also had higher SAT scores (self-
reported), leading Mayer and colleagues to conclude not only that emotional intelligence
is a valid and measurable concept but also that general intelligence and emotional intel-
ligence may be related: Those who are high in emotional intelligence are also smarter in
the traditional sense (Mayer et al., 2000). Another review found individuals with higher
emotional intelligence tended to have better social relationships for both children and
adults, better family and intimate relationships, were perceived more positively by oth-
ers, had better academic achievement, were more successful at work, and experienced
greater psychological well-being (Mayer, Roberts, et al., 2008).
Another example of research supporting the role of emotional intelligence in real-
world settings has been in the field of medicine. Studies have supported that medical
school students with higher emotional intelligence tended to perform better in courses
related to patient relationships, or “bedside manners” (Libbrecht et al., 2014). In this
sample of students, success appeared to be related more to the individual ’s ability
to regulate their own emotions, as compared to their ability to understand the emo-
tions of others. There has also been reported evidence for emotional intelligence being
related to physician competence and areas of improved physician–patient interactions,
including enhanced communication and more empathic and compassionate patient
care (Arora et al., 2010).
The Nature/Nurture Issue Regarding Intelligence
7.10 Evaluate the influence of heredity and environment on the development
of intelligence.
Are people born with all of the “smarts” they will ever have, or do experience and learn-
ing count for something in the development of intellect? The influence of nature (hered-
ity or genes) and nurture (environment) on personality traits has long been debated in
the field of human development, and intelligence is one of the traits that has been exam-
ined closely. to Learning Objective 8.2.
TWIN AND ADOPTION STUDIES The problem with trying to separate the role of genes
from that of environment is that controlled, perfect experiments are neither practical
nor ethical. Instead, researchers find out what they can from natural experiments, cir-
cumstances existing in nature that can be examined to understand some phenomenon.
Tw i n s t u d i e s are an example of such circumstances.
Identical twins are those who originally came from one fertilized egg and, there-
fore, share the same genetic inheritance. Any differences between them on a certain trait,
then, should be caused by environmental factors. Fraternal twins come from two dif-
ferent eggs, each fertilized by a different sperm, and share only the amount of genetic
material that any two siblings would share. to Learning Objective 8.3. By com-
paring the IQs of these two types of twins reared together (similar environments) and
reared apart (different environments), as well as persons of other degrees of relatedness,
researchers can get a general, if not exact, idea of how much influence heredity has over
the trait of intelligence (see Figure 7. 7 ). As can be easily seen from the chart, the greater
the degree of genetic relatedness, the stronger the correlation is between the IQ scores of
those persons. The fact that genetically identical twins show a correlation of 0.86 means
that the environment must play a part in determining some aspects of intelligence as
measured by IQ tests. If heredity alone were responsible, the correlation between genet-
ically identical twins should be 1.00. At this time, researchers have determined that the
estimated heritability (proportion of change in IQ within a population that is caused by
hereditary factors) for intelligence is about .50 or 50 percent (Plomin & DeFries, 1998;
Plomin & Spinath, 2004). Furthermore, the impact of genetic factors increases with
increasing age, but the set of genes or genetic factors remains the same. The effects of the
same set of genes becomes larger with increasing age (Posthuma et al., 2009).
Emotional intelligence includes empathy,
which is the ability to feel what others
are feeling. This doctor is not only able to
listen to her patient’s problems but also
is able to show by her facial expression,
body language, and gestures that she
understands how the patient feels.heritability
degree to which the changes in some
trait within a population can be con-
sidered to be due to genetic influences;
the extent individual genetic differ-
ences affect individual differences in
observed behavior; in IQ, proportion of
change in IQ within a population that
is caused by hereditary factors.