There has been a growing concern that modern society is increasingly lonely. In 2006, a New York Times article "The Lonely American Just Got a Bit Lonelier" highlighted research that shows a decline in social engagement--people are less likely to join clubs, have fewer close friends, and are less likely to perceive others as trustworthy. However, studies have also shown an increase in extraversion and self-esteem, which suggests loneliness is decreasing.

In an effort to study the societal trend of loneliness, researchers from the University of Queensland and Griffith University conducted an analysis of data on high school and college students. The study is published in Personality and Social Psychology Bulletin.

In the first study, the researchers examined past studies that utilized the Revised UCLA loneliness scale (R-UCLA) to analyze changes in loneliness over time, and gender differences in loneliness. The studies focused on college students through the year 1978 to 2009. Analysis of the studies showed a modest decline in loneliness over time. Female students reported lower loneliness than male college students.

Study 1 used a small sample of studies, which limits the reliability of the analysis. The literature also focused on college students, which is not necessarily a representative sample of the general population. Study 2 aimed to address these limitations.

Study 2 utilized a large representative sample of high school students from the Monitoring the Future (MTF) project. The MTF project surveyed the behaviors, attitudes and values of American high school students. Overall, high school students reported a decline in loneliness from 1991 to 2012.

The researchers examined specific items within the MTF data to determine if various aspects of loneliness demonstrated differing trends. The MTF project assessed feeling lonely, feeling left out, and desiring more close friends, which assess subjective feelings of isolation; the researchers termed this factor "subjective isolation." The second factor included items such as whether an individual has friends to talk to, turn to, and interact with, which measures a students' social environment and social support; the researchers labeled that factor "social network isolation."

Study 2 found that White high school students reported lower loneliness than Black students, Hispanic students, or other races. The study also found that subjective isolation declined, but social network isolation increased, which suggests that high school students perceive less loneliness but poorer social networks. High school students reported fewer friends with whom to interact, but less desire for more friends.

Lead researcher David Clark explains that "the trend in loneliness may be caused by modernization." Throughout history, modernization has changed the way people interact with one another. "People become less dependent on their families and need more specialized skills, which could lead to less interest in social support and more self-sufficiency," Mr. Clark says. "Over time, people are more individualistic, more extroverted, and have higher self-esteem."

More research on cultures outside of the U.S. is necessary to determine if modernization is the root cause of the observed results. "If other cultures show the same pattern of reduced loneliness in the face of poorer social networks, this would support the idea that modernization is responsible," Mr. Clark says. If other cultures do not show a similar pattern, then the cause is something more specific to American culture.