Heredity
may be the reason some people feel lonely
Newswise — Heredity helps
determine why some adults are persistently lonely, research
co-authored by psychologists at the University of Chicago
shows.
Working with colleagues in
The Netherlands, the scholars found about 50 percent of
identical twins and 25 percent of fraternal twins shared
similar characteristics of loneliness. Research on twins is
a powerful method to study the impact of heredity because
twins raised together share many of the same environmental
influences as well as similar genes, thus making it easier
to determine the role of genetics in development.
“An interesting
implication of this research is that feelings of loneliness
may reflect an innate emotional response to stimulus
conditions over which an individual may have little or no
control,” the research team writes in the article, “Genetic
and Environmental Contributors to Loneliness in Adults: The
Netherlands Twin Register Study” published in the current
issue of the journal Behavior Genetics.
Psychologists had
previously thought loneliness was primarily caused by
shyness, poor social skills, or inability to form strong
attachments with other people.
Scholars are becoming
increasingly interested in the role loneliness plays in
health. Other work by John Cacioppo, the Tiffany & Margaret
Blake Distinguished Service Professor in Psychology at the
University of Chicago and a member of the research team,
shows that loneliness is a risk factor for heart disease.
Loneliness is also at the base of a number of emotional
conditions, such as self-esteem, mood, anxiety, anger and
sociability.
A caring environment can
help lonely people overcome their feelings, but the research
also shows that in some cases, the impact of heredity is
stronger, said Cacioppo, who was joined in the study by
Louise Hawkley, a Senior Research Scientist in Psychology at
the University.
The lead author of the
article was Dorret Boomsma, a Professor of Biological
Psychology at the Free University in Amsterdam. Boomsma is
one of the world’s most prominent researchers on twins and
heredity. Other researchers with the project are Gonneke
Willemsen of the Free University and Conor Dolan of the
University of Amsterdam.
The study was based on
data from 8,387 twins in The Netherlands, who have been
surveyed regularly since 1991. Smaller, earlier studies done
with children suggested that the tendency toward loneliness
could be inherited. The Dutch-U.S. study is the first to be
done on adults and shows that heredity persists in playing a
role in loneliness as people age.
As part of the study, the
twins were asked to rate to what extent certain descriptions
applied to them, such as “Others don’t like me,” “I lose
friends very quickly,” “I feel lonely,” and “Nobody loves
me.”
People noted a wide
variety of responses to the descriptions, with 35 percent of
the men and 50 percent of the women reporting moderate to
extreme feelings of loneliness.
The researchers write that
loneliness may have developed early in human evolution as a
response by hunter-gathers facing conditions of
undernourishment who may have decided not to share their
food with their families. By surviving a famine, those early
ancestors would be able to propagate during periods of
plenty, the researchers theorized. In developing loneliness
as an adaptation to survival, these early humans also
developed dispositions toward anxiety, hostility, negativity
and social avoidance, they said.
The research was funded by
the Netherlands Organization for Scientific Research and the
U.S. National Institute of Aging.
“The genetics of social
behavior is an intriguing and expanding area of research,”
said Jeffrey W. Elias, cognitive aging specialist at the
National Institute on Aging (NIA). “This study suggests
there may be a genetic component to loneliness, such that
people with a predisposition to loneliness may process
social interaction and information differently. This is
important to know as we investigate the effects of behavior
and emotion on health and longevity